Thursday, December 27, 2007
Guidelines For First Trimester Ultrasound Examination
Obstetrics & Gynecology Guidelines
Blood Transfusion in Obstetrics,Green-top Guideline, May 2015
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- Diagnosis of Pregnancy
- ▼ December (15)
- DR Alaa Mosbah
- Mansoura, Egypt
- Dr.Alaa Mosbah MD OBS and GYN I started my career as a House Officer (Intern) at Mansoura University Hospitals. This is one of the largest Teaching Hospitals in Egypt. This was followed by 12 month training in general surgery ,medicine and OBS & GYN at the Egyptian military air force hospital. My experience in Obstetrics and Gynaecology started as a Resident Doctor (Registrar) and Assistant Lecturer (Senior Registrar) at the Department of Obstetrics and Gynaecology, Mansoura University Hospitals with more than 8000 annual delivery rate. At 2007, Lecturer of Obstetrics & Gynaecology at Mansoura University Teaching Hospitals.Currently ,I am A.Prof. of Obstetrics & Gynaecology. Also ,I am chief PBL Tutor ,Instructor , , Examiner and programme director deputy in Mansoura-Manchester Programme for Medical Education ..Also i am consultant in laparoscopic surgery .
بطانة الرحم المهاجره (الأندوميتريوزس) و عقم السيدات و الام الحوض
يعتبر مرض بطانة الرحم المهاجره (الأندوميتريوزس) من الأمراض المنتشرة بين السيدات. وتتمثل أعراض ألمرض فى وجود الام بالحوض وأسفل الظهر بالإضافة الى العقم . وقد تبين وجود مرض بطانة الرحم المهاجره فى 20% - 40% من حالات العقم اثناء عمل منظار البطن التشخيصي لها. كما تبين وجود بطانة الرحم المهاجره فى اكثر من 20% من الحالات التى تعانى من الآم الحوض المزمنة. كذلك فهو مسئول عن الام الدوره الشهريه في نسبه كبيره من البنات بعد سن البلوغ و اللاتي لا يستجبن للمسكنات . وغالبا ما يتم تشخيص بطانة الرحم المهاجره متأخرا وذلك لوجود اعراض متباينة للمرض وكذلك لتشابه اعراض المرض مع امراض اخرى مثل التهابات الحوض. وبالرغم من ان منظار البطن يعتبر الوسيلة المثلى حتى الأن لتشخيص بطانة الرحم المهاجره قأن بعض الحالات لا يتم اكتشافها عن طريق منظار البطن وذلك اما لصعوبة وصول المنظار الى مكان الإصابة او لوجود اصابات عديمة اللون او وجود اصابات مختفية تحت الغشاء البريتونى . وتوجد عدة وسائل لتشخيص بطانة الرحم المهاجره مثل قياس نسبة (سى أيه-125)فى الدم ولكنة غير دقبق . كما يمكن استخدام اشعة الرنين المغناطيسى ولكنها مكلفة جدا وتحتاج الى خبرة كبيرة و غير دقبقة احيانا. وتعتبر الموجات فوق الصوتية وسيلة امنة و بسيطة وغير مكلفة و من الممكن استخدامها فى تشخيص التغدد الرحمى وبخاصة بعد التطور الكبير فى اجهزة الموجات فوق الصوتية .و تسبب بطانة الرحم المهاجره عقم السيدات عن طريق حدوث التصاقات بقناة فالوب وتدمير المبيضين وافراز مواد كميائية تمنع حدوث الاخصاب .و يعتبر منظار البطن الوسيلة المثلى لتشخيص و علاج بطانة الرحم المهاجره باستئصال او كي اكياس التغدد الرحمى و ازالة الالتصاقات بقناة فالوب .
د. علاء مصباح
استاذ التوليد وامراض النساء
كلية طب المنصورة
The 1st laparoscopic salpingo-oophrectomy for large ovarian tumor in OBS and GYN depart.in mansoura
Laparoscopic RT.salpigo-oophrectomy for large ovarian tumor in child aged 10 years
اليوم . الثلاثاء، 22 يناير 2013 الدقهليه - رشا النجار استطاع فريق جراحى جامعة المنصورة من تخليص طفله فى العااشرة من عمرها من الامها التى عانت منها على مدار عامان باجراء عملية منظار دون ان تعرف السبب حيث استشعرت سارة كبر بحجم بطنها وقام والديها بالكشف عليها لدى عدة اطباء بمسقط راسها بمدينة المحلة الكبرى حيث لم يتم تحديد سبب الالامها
الى ان قرر اهل الطفله التوجه الى مستشفى جامعة المنصورة ليقوم الفريق الطبى بقسم امراض النسا بفحصها وكانت المفاجاه هى وجود ورم متوسط الحجم لكن نظرا لصغر سن المريضه وانها فى مرحلة عدم البلوغ فقد كان من الصعوبه التدخل الجراحى وقرر الدكتور علاء مصباح بالتدخل لاسستئصال الورم ولاول مرة عن طريق المنظار بمعاونة الفريق الطبى وعلى راسهم الدكتورة هبه نجيب حث تم ازالة الورم من المبيض الايمن والانبوب الايمن بالمنظار الجراحى
Radiation exposure during pregnancy
(1) Ionizing rays (x-rays),
(2) Cosmic rays,
(4) Ultrasound, and
(5) Electromagnetic fields.
1- Ionizing rays
X-rays are the most frequent iatrogenic exposure besides prescription medications. During their careers, all obstetricians and gynecologists are asked about the effects of radiation exposure on a pregnancy, and they are expected to be able to judge the need for diagnostic or therapeutic radiation. The effects of radiation are well studied, but as cohort age and long-term effects become clear, information continues to evolve in this ever-changing field. Knowledge about exposures also changes rapidly.
The primary exposures are diagnostic x-rays, radio-pharmaceuticals, workplace exposures, and environmental exposures such as those that occurred after the Three Mile Island and Chernobyl nuclear reactor accidents, and in Iraq following the Gulf War II. Documented effects include (1) intrauterine lethality, (2)organ malformation, (3)mental impairment, and later-onset (4) leukemia and solid tumors.
X-rays are measured in several types of units, the most important of which are the radiation absorbed dose (rad), which is the measure in the United States, and the gray (Gy), which is an international measure. Both rads and grays typically refer to single-time exposures (eg, diagnostic procedures). The roentgen equivalent man (rem) unit of measure and sievert (Sv) unit are used to quantify radiation exposure over time (eg, environmental releases). Conversion factors for these measurements are 1 Gy equals 100 rad and 1 Sv equals 100 rem.
X-rays have both immediate effects and delayed effects:
Immediate (deterministic) effects are usually intrauterine, often post-conceptual, effects involving damage to growing and pattern-forming cell populations. If the exposure occurs when cell numbers are few, such as during the blastocyst or pre-implantation stage, very early abortion or implantation failure occurs. These effects demonstrate both a dose-response curve and a threshold below which no effects are observed.
As with other teratogens, the embryonic stage is crucial because windows exist for the appearance of effects. The fetal dose is also critical, and a simple application of a maternal calculated dose should not be substituted.
The damage threshold begins at 0.1-0.15 Gy, which causes abortion at pre-implantation, and extends to 1 Gy, which is associated with fetal death in utero at term. Organogenesis represents a window of sensitivity for the fetus during gestational weeks 3-7. The threshold is thought to be 0.05-0.5 Gy.
Skeletal defects have been noted in humans, most particularly reduced head circumference. Animal data point to more frequent defects of the genitourinary system and eye in addition to skeletal effects. Severe mental retardation is another human effect noted at this threshold (0.05-0.5 Gy). The window for these effects is gestational weeks 8-25. Mental retardation has been noted at maternal doses of 1.5 Gy. Fetuses exposed during weeks 8-25 also demonstrate an onset of effects secondary to radiation. These effects include mental retardation, a downward shift in intelligence quotient (IQ) of 30 IQ units/Gy, lower school performance, and unprovoked seizure. All effects are more severe if the exposure occurs during gestational weeks 8-15. Importantly, note that while infants of normal intelligence remain within 1 standard deviation of normal following exposure, borderline infants are rendered mentally retarded at relatively low exposures.
These effects do not show a threshold, and they occur in the later years of the exposed individual’s life. Fetal x-ray exposures are associated with later-onset childhood leukemia and solid tumors. The demonstrated relative risk in multiple case-control studies is 1.39 (95% confidence interval: 1.3-1.49). This increased risk was documented by the very large Oxford Survey of Childhood Cancers, and the finding was confirmed by multiple US and European studies. The increased risk is thought to occur following an exposure of 0.05 Gy.
Thyroid cancer in childhood is a special concern. Multiple studies have shown that direct external exposure of children’s thyroids results in an increased frequency of cancer. Such exposures occurred following the Chernobyl accident and during medical procedures. The lag time until detection of cancer is 5 years after exposure. In contrast, in utero exposure during the second and third trimester of pregnancy (eg, Chernobyl, maternal thyroid ablation) is associated with an onset of childhood thyroid cancer before the 5-year lag time; these cancers are associated with increased morbidity and aggressiveness.
Radiation is a dose-dependent teratogen. Below a certain threshold, radiation levels are similar in exposed populations and control populations who have received only background radiation.1 A fetus is most vulnerable to radiation-induced central nervous system damage 8 to 15 weeks after conception . Radiation from x-ray and CT scans is measured in rad, rem, gray, and sievert (1 rad = 1 rem = 0.01 Gy = 0.01 Sv).
The United States Centers for Disease Control and Prevention’s Radiation Safety Committee recommends that fetuses of laboratory workers not receive more than a cumulative dose of 500 mrad during the entire gestation period. This occupational exposure guideline is one-tenth of the safe dose and should not be confused with the teratogenic-threshold dose. Pregnant women exposed to <5000 mrad have similar pregnancy outcomes to controls who have received only background radiation.
Most radiodiagnostic examinations expose fetuses to less than 5000 mrad of radiation .X-ray examination of the abdomen is associated with 250 mrad, and an abdominal CT scan with 3000 mrad. There is no significant increase in major malformations in pregnant women inadvertently exposed to these radiation doses. These women should be reassured and counseled appropriately.
Estimated fetal radiation doses during some common radiodiagnostic procedures
FETAL DOSE (MRAD)
Upper gastrointestinal series
Lumbar spine radiography
Hip and femur radiography
Abdominal (kidneys, uterus, bladder) radiography
Clearly, preventing exposure during the first trimester is advisable. Clear counseling is needed for patients with conditions that require uptake scans or radio-nuclide therapy. Patients should be advised that no known safe dose exists in regard to later-onset childhood cancers. The balancing of risk to both patients (fetus and mother) must take into account the value that any given diagnostic test will have for decision-making. For occupational exposures, the limit is 1 mSv after pregnancy notification.
2- Cosmic rays:
Cosmic radiation is ionizing radiation by heavy particles, such as protons and helium nuclei that originate outside the earth. This form of ionizing radiation is most evident at very high altitudes. Primary exposure requires many in-air hours; therefore, airplane crewmembers and pilots, rather than passengers, are typically at risk.
Relatively few studies have been performed on human exposure to cosmic radiation. Risks are real, but the medical community and the general public have little awareness of them.
Two organizations, the US National Council on Radiation Protection and Measurement (NCRP) and the International Commission on Radiologic Protection (ICRP), provide the following recommendations on permissible doses:
General public - 1 mSv
Aircrews - 20 mSv/y averaged over 5 years (maximum 50 mSv/year)
Fetuses - 2 mSv (not to exceed 0.5 mSv/month)
Notably, aviators generally have a lower overall incidence of cancer compared to the general population. The risks of all other forms of transportation outweigh those of flight, although an association exists between frequent flying and certain specific cancers, most notably brain, colon, and hematopoietic cancers.
Also, ionizing radiation has the previously noted fetal effects of decreased head circumference, mental retardation, and childhood cancer.
Aviation workers can easily exceed the NCRP and ICRP limit recommendations. Charter jet crews and passengers fly at higher altitudes with more consequent exposure. Changes in intensity occur with changes in solar flare activity on the sun, and the intensity may exceed 10 mSv/h at 42,000 ft. The US Federal Aviation Administration and the US Occupational Safety and Health Administration recognize flight crews as individuals exposed to radiation. Computer systems are available to calculate exposures, but these systems are not mandatory.
Health care providers should obtain complete occupational histories and discuss risk of exposure with pregnant patients. Given the variability of exposure and that no easy monitoring is possible, any mandatory cut-off or exclusion of pregnant workers from their jobs would be potentially discriminatory and may lead to risks to the child due to altered socioeconomic status.
Microwaves are a form of electromagnetic radiation with particularly long wavelengths. In contrast to ionizing radiation, which travels in extremely short, high-energy waves, energy in microwave radiation affects objects and cells by thermal action only. Microwaves raise the temperature within cells and are cytotoxic to individual cells only at high exposures. No specific DNA-damaging mechanism exists, and no stochastic effects are observed in exposed populations.
4- Ultrasound:Ultrasound involves the creation of very high-frequency sound, emission of this sound, and analysis of how the sound alters upon encountering objects of different densities when reflected back to the emitter. Physical effects, such as well-contained thermal effects, occur when the vibration at these very high speeds is used (e.g. between the paddles of a harmonic scalpel).The energy of ultrasound is carried by the physical particles of the media and objects affected. The energy does not reach an ionizing level, and no DNA-specific effects are observed.
5- Electromagnetic fields:
Despite multiple studies, including some very large studies, the low-energy electromagnetic fields generated by power lines, video displays, and other electric and electronic devices have no demonstrable effects. Some of these studies have been conducted in response to clusters of events, such as increased spontaneous abortion rates in a specific area.
Infertility evaluation & treatment
Infertility is the inability to conceive, but a couple are regarded as infertile if after regular sexual intercourse they have not conceived in 2 years [National Collaborating Centre for Women's and Children's Health, 2004].
Infertility is classed as primary in couples who have never conceived and secondary in couples who have previously conceived [National Collaborating Centre for Women's and Children's Health, 2004].
Infertility may be categorized into unexplained (30%), or secondary to ovulatory failure (27%), male factors (19%), tubal factors (14%), or endometriosis (5%) [NHS CRD, 1992; De Kretser, 1997; Templeton, 2000]. The presence of disorders in both the man and the woman has been reported to occur in about 39% of cases [Thonneau et al, 1991; National Collaborating Centre for Women's and Children's Health, 2004].
The prevalence of infertility is around 14% in European countries, affecting one in seven couples [National Collaborating Centre for Women's and Children's Health, 2004].
Of all couples attempting to conceive, 16% are unsuccessful after 1 year. This reduces to 8% after 2 years and 7% after 3 years [National Collaborating Centre for Women's and Children's Health, 2004].
Infertility is more common with increasing age: female fertility declines with age although the effect on male fertility is less clear. With regular sexual intercourse only 6% women aged 35 years and 23% of those aged 38 years will have failed to conceive after 3 years [National Collaborating Centre for Women's and Children's Health, 2004].
The number of couples seeking help has increased although it is not thought that there has been a major increase in the prevalence of infertility. Theories such as a decline in sperm count due to environmental factors are controversial. Behavioural factors such as a tendency to delay childbearing may play a role [Himmel et al, 1997; Templeton, 2000].
Causes of infertility in women
1.Disorders of ovulation
2.Premature ovarian failure
3.Polycystic ovarian syndrome: often associated with 4.hirsutism, obesity, acne, and menstrual irregularity.
6.Anterior pituitary macro or microadenoma may alter 7.prolactin secretion and lead to amenorrhoea and anovulation. Although stress may cause a transient rise in prolactin, levels higher than 1000 ml/litre suggest an adenoma.
8.Hypogonadotrophic hypogonadism: the commonest cause is excessive exercising, being underweight or both. People with anorexia nervosa are normally amenorrhoeic.
9.Sheehan's syndrome (panhypopituitarism most often following massive postpartum haemorrhage or trauma) is now very rare.
10.Kallmann's syndrome (amenorrhoea and anosmia due to congenital lack of hypothalamic production of gonadotrophin-releasing hormone) is rare.
11.Thyroid: hyperthyroidism and hypothyroidism may lead to menstrual disorders and ovulatory dysfunction.
12.Adrenal: Cushing's syndrome and congenital adrenal hyperplasia may cause anovulation.
13.Tubal, uterine and cervical factors
14.Genital tract infection causing tubal damage: chlamydial infection is a major risk factor [Land and Evers, 2002].
15.Previous pelvic surgery causing tubal damage or adhesions, or previous cervical surgery causing scarring or shortening of cervix and, rarely, cervical stenosis.
16.Submucosal fibroids may distort the uterine cavity and impair implantation [Campbell and Monga, 2000].
18.Cervical mucus defect or dysfunction
19.Endometriosis: tubal distortion and limitation of fimbrial motility due to pelvic adhesions.
Nonsteroidal anti-inflammatory drugs, in particular indometacin, can inhibit ovulation.
Chemotherapy with cytotoxic drugs can induce ovarian failure, which may be permanent.
Recreational drugs, such as marijuana and cocaine, have also been associated with impaired ovulatory and tubal function.
[Dukes, 1996; Janssen and Genta, 2000; National Collaborating Centre for Women's and Children's Health, 2004]
Occupational/environmental factors which may affect fertility include shift work, intense physical workload, pesticides, solvents and formaldehyde [National Collaborating Centre for Women's and Children's Health, 2004].
Psychogenic factors may affect fertility but studies have not consistently shown this [Himmel et al, 1997].
Significant systemic illness e.g. thyroid problems
[Cooke, 1996; Hargreave and Mills, 1998; Chen and Brzyski, 1999; Chambers, 1999; Campbell and Monga, 2000; Hamilton-Fairley and Taylor, 2003; National Collaborating Centre for Women's and Children's Health, 2004; Symonds and Symonds, 2004; HFEA, 2004b]
Causes of infertility in men :
2.Commonest cause of male subfertility: reduced count of mainly dysfunctional spermatozoa (oligoasthenoteratozoospermia) of unknown cause
3.Congenital, e.g. Klinefelter's syndrome (karyotype 47 XXY, small testes and sterility)
4.Hypogonadotrophic hypogonadism, e.g. Kallmann's syndrome
5.Pituitary causes, e.g. hyperprolactinaemia from a pituitary adenoma
6.Genital tract abnormalities
8.Past history of infection, e.g. mumps orchitis; epididymitis and prostatovesiculitis may also lead to infertility
9.Congenital absence of vas deferens: 1-2% of infertile men
10.Testicular tumour: may be palpable on examination
11.Maldescended testes: absence of testes on examination
12.Varicocele: present in up to approximately 25%-40% of subfertile men, although its association with infertility is not clear [Wong et al, 2000]
13. Drugs :
Sulfasalazine, neuroleptics, and nitrofurantoin can affect semen quality and cause oligospermia. The effect is usually reversible on withdrawal of medication [Dukes, 1996; National Collaborating Centre for Women's and Children's Health, 2004].
Chemotherapy with cyotoxic drugs can induce permanent azoospermia [National Collaborating Centre for Women's and Children's Health, 2004].
Beta-blockers, cimetidine, psychotrophic drugs, and spironolactone can cause impotence or ejaculatory dysfunction [National Collaborating Centre for Women's and Children's Health, 2004].
The use of drugs such as anabolic steroids and cocaine can adversely affect the quality of semen.
[Dukes, 1996; National Collaborating Centre for Women's and Children's Health, 2004]
14.Other factors :
Ejaculation disorders, e.g. retrograde ejaculation, impotence
Environmental factors which may affect fertility include agricultural chemicals, X-ray exposure, solvents, and heavy metals [National Collaborating Centre for Women's and Children's Health, 2004].
Antibodies against spermatozoa, e.g. post vasectomy
Exposure of testes to heat
Psychogenic stress and its association with infertility in men is not clear. A higher incidence of male sexual disturbances has been observed in couples undergoing fertility investigation and treatment [Saleh et al, 2003; National Collaborating Centre for Women's and Children's Health, 2004].
Significant systemic illness, e.g. cardiac failure, chronic renal failure, neoplasia, uncontrolled diabetes, liver cirrhosis, thyrotoxicosis.
[Wu, 1996; De Kretser, 1997; Himmel et al, 1997; Hargreave and Mills, 1998; Chambers, 1999; Hirsh, 2003]
Likely outcomes of infertility :
For couples who have been trying for less than a year, the conception rate is between 80% and 90%.
For couples who have been trying to conceive for up to 3 years, the conception rate is about 40% in a 1-year period (equivalent to a monthly fecundity rate of 4-5%) if the woman is aged about 30 years.
For couples who have been trying for more than 3 years, the conception rate is still up to 25% in a 1-year period.
If a male or female subfertility factor has been identified, there is still a likelihood of spontaneous conception, although the success rates may be lower.
[NHS CRD, 1992; Himmel et al, 1997; Hargreave and Mills, 1998; Te Velde and Cohlen, 1999].
In vitro fertilization (IVF): the overall live birth rate per treatment cycle is 21.8% (25.1% for women aged less than 38 years). If frozen embryos are used the success rate is about 12% per treatment cycle. After five attempts, just over half of women aged under 34 years will have conceived [HFEA, 2004a; HFEA, 2004b]. One in 20 pregnancies that result in a live birth will be a multiple pregnancy. Twins are much are more common than triplets (ratio of 15:1) [National Collaborating Centre for Women's and Children's Health, 2004].
Intracytoplasmic sperm injection (ICSI): the overall live birth rate per embryo transfer is 28.7% (25.7% for women over 38 years) .
Intrauterine insemination (IUI) has a pregnancy rate of 9% per treatment cycle using ovulation stimulation in couples with unexplained infertility [National Collaborating Centre for Women's and Children's Health, 2004].
Donor insemination (DI) has a live birth rate of about 10-12% with each attempt in women under 30 years, and 9% in women aged 35-39 years [HFEA, 2004b].
Oocyte donation has a live birth rate of 25-40% with each attempt (eggs donated by women under 36 years)[HFEA, 2004b].
Embryo donation has a live birth rate of 16.8% using frozen embryos and 27.3% using fresh embryos [Lee and Yap, 2003].
Gamete intrafallopian transfer (GIFT) has a pregnancy rate of 25-30% in any one treatment cycle [HFEA, 2004b].
Tubal surgery: reported pregnancy rates range between 5% and 50%, with the severity of tubal damage being closely linked to outcome [National Collaborating Centre for Women's and Children's Health, 2004].
Reversal of sterilization: pregnancy rates of up to 85.7% have been reported, although rates depend on the type of previous surgery and age. A successful outcome is more likely in younger women [Cohen et al, 1999; Yoon et al, 1999; Tourgeman et al, 2001; Hanafi, 2003].
Reversal of vasectomy results in subsequent pregnancy rates ranging between 35% and 71% [Himmel et al, 1997].
Medical treatment for male factor infertility is effective only if the cause is hypogonadotrophic hypogonadism, where 80% of men have achieved a positive sperm count [National Collaborating Centre for Women's and Children's Health, 2004].
Medical treatments for ovulatory dysfunction caused by hyperprolactinaemia results in an ovulation rate of 70-80% [Hamilton-Fairley and Taylor, 2003].
Pulsatile gonadotrophin-releasing hormone for hypothalamic amenorrhoea results in conception rates of 80-90% after 12 months' use [Hamilton-Fairley and Taylor, 2003].
Management Issues :
Assessment and investigations for infertility are not generally advised until the couple have been unable to achieve a pregnancy after a year of unprotected intercourse. Some people who present with concerns about their fertility need only simple reassurance that the chance of conception is 84% in the first year if they do not use contraception and have regular sexual intercourse. About half of couples who do not conceive in the first year will conceive in the second year (a cumulative pregnancy rate of 92%) [National Collaborating Centre for Women's and Children's Health, 2004].
Regular sexual intercourse (two or three times a week) throughout the cycle should ensure that intercourse falls within the fertile period. Timing of intercourse using temperature charts and luteinizing hormone detection methods causes stress and has not been shown to improve conception rates. They are therefore not recommended [Hargreave and Mills, 1998; National Collaborating Centre for Women's and Children's Health, 2004].
Folic acid supplements should be taken whilst trying to conceive and for the first 12 weeks of pregnancy in order to reduce the risk of neural tube defects. Most women should take 400 micrograms daily. A higher dose of 5 mg daily is recommended for women who either have a family history of neural tube defect, who have had a baby with a neural tube defect, who are taking antiepileptic medication, or who have coeliac disease [Wald, 1991; Lumley et al, 2003; National Collaborating Centre for Women's and Children's Health, 2004].
Rubella status should be checked. If seronegative, rubella vaccination is indicated and the woman should be advised not to become pregnant within 1 month of the vaccination. Note: the Department of Health has advised that seronegative women should be vaccinated using MMR (measles, mumps, and rubella) since the Department is no longer able to secure supplies of licensed rubella vaccine [CMO, 2003].
Cervical screening should be offered in accordance with the national cervical screening programme guidance [National Collaborating Centre for Women's and Children's Health, 2004].
For further information see the PRODIGY Preconceptual counselling guidance.
Assessment of the infertile couple in primary care
When should I assess?
Couples who are concerned about their fertility should be offered an initial assessment (history and examination) in primary care. Specifically enquire about lifestyle and sexual history to identify couples who may be less likely to conceive [National Collaborating Centre for Women's and Children's Health, 2004].
Couples who have not conceived after 1 year of regular unprotected sexual intercourse, or have been identified as less likely to conceive, should also be offered initial investigations, e.g. semen analysis, assessment of ovulation, or both [National Collaborating Centre for Women's and Children's Health, 2004].
How should I assess the woman?
A full medical, sexual, and social history should include:
Maternal age (fertility decreases with age)
Previous children born to the woman, previous pregnancies and miscarriages (with same or different partner)
Length of time trying to conceive, and frequency and difficulties of sexual intercourse
Length of time since stopping contraception and type of contraception
Menstrual cycle details: including length of cycle and symptoms and signs of ovulation, e.g. ovulatory discomfort, changes in cervical mucus
Cervical smear history and previous pelvic surgery, e.g. appendicitis
Symptoms of pelvic inflammatory disease or endometriosis, e.g. dyspareunia and dysmenorrhoea
Past history of sexually transmitted diseases or pelvic inflammatory disease [World Health Organization Task Force on the Prevention and Management of Infertility, 1995]
Systemic or debilitating diseases including thyroid dysfunction, diabetes, inflammatory bowel disease, and anorexia nervosa
Details of occupation for possible exposure to hazards that can reduce fertility, e.g. pesticides, nitrous oxide, formaldehyde and solvents [National Collaborating Centre for Women's and Children's Health, 2004].
Lifestyle factors that may affect fertility, e.g. smoking, alcohol intake, excessive exercise, stress. Excessive travelling that limits optimal coital timing may indirectly affect fertility.
[Chambers, 1999; Symonds and Symonds, 2004]
Pelvic examination may identify factors causing infertility, such as vaginal infection or tenderness indicating endometriosis or pelvic inflammatory disease. Bimanual examination may reveal fibroids or an ovarian cyst [Hargreave and Mills, 1998; Chambers, 1999].
Also look for obesity (associated with lower fertility), hirsutism, acne, or both (associated with polycystic ovary syndrome), and galactorrhoea (suggestive of hyperprolactinaemia) [Chambers, 1999].
Mid-luteal phase progesterone levels should be checked in all women to confirm ovulation. The sample should be taken 7 days before the expected period (day 21 in a 28‑day cycle) [National Collaborating Centre for Women's and Children's Health, 2004].
In women with prolonged irregular menstrual cycles, depending on the timing of menstrual periods, serum progesterone may need to be taken later in the cycle, and repeated weekly thereafter until the next menstrual cycle starts [National Collaborating Centre for Women's and Children's Health, 2004].
Serum gonadotrophins (follicle-stimulating hormone and luteinizing hormone) should be measured in all women with irregular menstrual cycles. Women with high levels of gonadotrophins are likely to have reduced fertility [National Collaborating Centre for Women's and Children's Health, 2004].
Thyroid function tests should only be undertaken in women with symptoms of thyroid disease. Women with possible fertility problems are no more likely than the general population to have thyroid disease [National Collaborating Centre for Women's and Children's Health, 2004].
Prolactin estimation should be reserved for women with an ovulatory disorder, galactorrhoea or a suspected pituitary tumour [National Collaborating Centre for Women's and Children's Health, 2004].
Chlamydia screening. NICE recommends that all women who will be undergoing uterine instrumentation should be tested for chlamydia, as infertility investigations may result in iatrogenic pelvic inflammatory disease. Although the prevalence of Chlamydia trachomatis is only 1.9% in subfertile women, the number of people diagnosed with uncomplicated chlamydia infection has risen steadily since 1993 particularly in the 16-19‑year-old age group. We would therefore recommend that chlamydia screening should be part of the assessment of all women presenting with infertility. If the test is positive, women and their partners should be referred for appropriate management and contact tracing [PHLS et al, 2000; National Collaborating Centre for Women's and Children's Health, 2004].
How should I assess the man?
A full medical, sexual, and social history should include:
Previous children born to the man (with same or different partner)
Length of time trying to conceive, and frequency and difficulties of sexual intercourse
Past history of mumps, sexually transmitted diseases, or testicular trauma [World Health Organization Task Force on the Prevention and Management of Infertility, 1995; Kennedy, personal communication, 2004]
Previous surgery e.g. herniorrhaphy
Previous urogenital pathology and treatment, e.g. undescended testis or orchidopexy
Systemic or debilitating diseases, e.g. cardiac failure, chronic renal failure, neoplasia, uncontrolled diabetes liver cirrhosis, thyrotoxicosis [Wu, 1996]
Details of occupation for possible exposure to pesticides, X-rays, solvents, paints, chemicals from smelting or welding [National Collaborating Centre for Women's and Children's Health, 2004].
Lifestyle factors that may affect fertility, e.g. smoking, alcohol intake, excessive travelling that limits optimal coital timing, excess exercise, stress, social or occupational situations that may cause testicular hyperthermia.
[Chambers, 1999; Symonds and Symonds, 2004]
Scrotal examination may reveal lumps (cancer, varicocele, or hernia), small, soft testes, or undescended testes in some cases.
The penis should be examined, including a check of the position of the urethral meatus, for structural abnormalities and signs of infection.
Assess secondary sexual characteristics.
Look for gynaecomastia.
[Cooke, 1996; Hargreave and Mills, 1998; Chambers, 1999]
One fresh semen specimen should be taken during the initial investigation. The specimen should be produced after 2-3 days abstinence from sex. The specimen should be sent to the laboratory as quickly as possible as analysis should be carried out preferably within 1 hour of production [Chambers, 1999; National Collaborating Centre for Women's and Children's Health, 2004].
Interpret using the World Health Organization (WHO) normal values:
Volume 2 ml or more
Liquefaction time within 60 minutes
pH 7.2 or more
Sperm concentration greater than 20 million/ml
Motility: 50% or more motile (grades a and b) or 25% or more with progressive motility (grade a) within 60 minutes of ejaculation. (Grade a is rapid progressive motility, with sperm moving swiftly, usually in a straight line; grade b is slow or sluggish progressive motility and sperm may be less linear in their progression.)
Vitality: 75% or more live
White blood cells: fewer than 1 million per ml
Morphology >30% normal forms (or >15% based on strict morphological criteria)
If the result of the first semen sample is normal, a repeat confirmatory test should ideally be taken 3 months after the initial test as this allows time for the cycle of spermatozoa to be completed.
If the result of the first semen sample is abnormal then a repeat test should be done. If there is a gross spermatozoa deficiency (azoospermia or severe oligospermia) then the repeat test should be done as soon as possible.
[National Collaborating Centre for Women's and Children's Health, 2004]
Which investigations are not generally recommended?
Basal body temperature charts do not reliably predict ovulation and are not recommended [Guermandi et al, 2001; National Collaborating Centre for Women's and Children's Health, 2004].
Ovulation predictor kits are widely available but there is no evidence that attempts to time intercourse to the menstrual cycle will result in improved conception rates and they are not recommended [Hargreave and Mills, 1998; Chambers, 1999].
The routine use of postcoital testing has no predictive value for pregnancy rates [National Collaborating Centre for Women's and Children's Health, 2004].
Screening for antisperm antibodies should not be offered, as there is no evidence of effective treatment to improve fertility [National Collaborating Centre for Women's and Children's Health, 2004].
Lifestyle advice ;
Smoking cessation is advisable for both men and women. Smoking, including passive smoking has been shown to be detrimental to fertility in women [Hughes and Brennan, 1996; Augood et al, 1998; Hull et al, 2000; BMA, 2004]. In men, although there is no clear evidence that smoking delays conception or affects fertility, it may affect sperm quality and general health [BMA, 2004].
Women should be advised to limit alcohol to 1 to 2 units once or twice a week. The evidence for a link between alcohol and female infertility is conflicting, and the limits for safe consumption are not known, but until more is known, low consumption of alcohol when trying to become pregnant and during pregnancy is advisable [DH, 2003; National Collaborating Centre for Women's and Children's Health, 2004].
Men should be informed that alcohol consumption within the Department of Health's recommendations of 3 to 4 units a day is unlikely to affect their fertility. Excessive alcohol consumption can be detrimental to semen quality [National Collaborating Centre for Women's and Children's Health, 2004].
Weight loss should be encouraged in women with a body mass index (BMI) greater than 29, as this is likely to increase their chance of ovulation and therefore conception. There is no proven association between male obesity and infertility, although obesity is associated with poorer general health, a reduction in sperm motility and increased DNA fragmentation [Rich-Edwards et al, 2002; Kort et al, 2003a; Kort et al, 2003b; National Collaborating Centre for Women's and Children's Health, 2004].
Women who have a body mass index of less than 19 and either amenorrhoea or irregular menstruation should be advised that gaining weight is likely to increase their chance of conception [National Collaborating Centre for Women's and Children's Health, 2004].
A well-balanced diet will contribute to general good health for both partners. Although there is little research on nutritional factors in infertility, there have been studies suggesting that nutritional deficiencies may play a role; e.g. vitamins C, D, E, selenium, zinc, and folate deficiencies may affect sperm quality [Wong et al, 2000].
There is no consistent evidence to link consumption of caffeinated beverages (tea, coffee, and cola) and infertility [National Collaborating Centre for Women's and Children's Health, 2004].
Men should be informed that although there is an association between an elevated scrotal temperature and reduced semen quality, it is uncertain whether wearing loose-fitting underwear improves semen quality [Tiemessen et al, 1996; Munkelwitz and Gilbert, 1998; National Collaborating Centre for Women's and Children's Health, 2004].
Secondary and tertiary care management
Specialist infertility clinics are the referral centres of choice. While many secondary care centres carry out a range of infertility treatments, in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), and donor insemination (DI) are usually only offered in tertiary care.
General practitioners may find that because of the strict confidentiality of the Human Fertilisation and Embryology Act, that they may not be sent information about their patient's assisted conception treatment. Sometimes letters will be set from the unit to the patient for them to release to their doctor as they see fit [Braude and Muhammed, 2003].
The Department of Health recommends that each primary care trust offer:
All women aged 23-39 who meet the NICE clinical criteria (see below) a minimum of one full cycle of IVF from April 2005. In the longer term it is expected that primary care trusts will progress towards fully implementing NICE guidance.
Priority to couples who do not already have a child living with them.
NICE recommend that all couples where the woman is aged 23-39 years at the time of treatment and who have an identified cause for their fertility problems (such as azoospermia or bilateral tubal occlusion) or who have infertility for at least 3 years' duration should be offered up to three stimulated cycles of in vitro fertilization treatment [National Collaborating Centre for Women's and Children's Health, 2004].
Assessment in secondary care
Investigations in women normally include tubal patency tests. Women who are not known to have comorbidities (e.g. pelvic inflammatory disease, endometriosis, or previous ectopic pregnancy) should be offered a hysterosalpingogram or hysterosalpingo-contrast-ultrasonography. Women thought to have comorbidities should be offered diagnostic laparoscopy and dye so that tubal and other pelvic pathologies can be assessed at the same time [National Collaborating Centre for Women's and Children's Health, 2004].
Investigations in men include an assessment of the sperm, starting with a review of results obtained from primary care investigations. In men with abnormal sperm, a more detailed examination is carried out which may include microbiological tests, sperm culture, endocrine tests, imaging of the urogenital tract, and testicular biopsy.
Types of fertility treatment
Ovulation induction with clomifene: clomifene is an effective treatment for anovulation, and may be used in selected women [Hughes et al, 2004]. The following needs to be noted:
The Committee on Safety of Medicines (CSM) recommend that no more than six cycles are given. Long-term cyclical therapy is also not recommended [CSM, 1995; ABPI Medicines Compendium, 2002].
NICE recommends treatment for up to 12 cycles. Use beyond this has been associated with an increased risk of ovarian cancer [Rossing et al, 1994; National Collaborating Centre for Women's and Children's Health, 2004].
Ovarian ultrasound monitoring of at least the first cycle where clomifene is prescribed is important, to titrate the drug to an appropriate dose and reduce the likelihood of multiple pregnancy [National Collaborating Centre for Women's and Children's Health, 2004].
Counselling, with regard to the risks of multiple pregnancy, ovarian hyperstimulation, foetal reduction, and possible risk of ovarian cancer, should be given.
Metformin or laparoscopic ovarian drilling may be offered to women with polycystic ovary syndrome who have not responded to clomifene [National Collaborating Centre for Women's and Children's Health, 2004].
Gonadotrophins may be offered to women with clomiphene-resistant anovulatory infertility, but carry a significant risk of multiple pregnancy. Careful monitoring with ultrasound is needed [Kennedy, personal communication, 2004].
Pulsatile gonadotrophin-releasing hormone and dopamine agonists are other treatments for the induction of ovulation.
Drug-induced ovarian suppression is no longer recommended for women with endometriosis because it does not improve pregnancy rates [Duckitt, 2003; National Collaborating Centre for Women's and Children's Health, 2004].
Dopamine agonists should be offered to women with ovulatory disorders secondary to hyperprolactinaemia. Investigations should be done to exclude a pituitary adenoma or extrapituitary tumour before proceeding with infertility treatment [Hamilton-Fairley and Taylor, 2003; National Collaborating Centre for Women's and Children's Health, 2004].
Gonadotrophin drugs are effective in improving fertility in men with hypogonadotrophic hypogonadism [National Collaborating Centre for Women's and Children's Health, 2004].
Surgical treatment :
Tubal surgery may be effective in women with mild tubal disease. Tubal catheterization or cannulation improves the chance of pregnancy in women with proximal tubal obstruction [National Collaborating Centre for Women's and Children's Health, 2004].
Laparoscopic surgery appears to improve the chance of pregnancy in women with all grades of endometriosis [National Collaborating Centre for Women's and Children's Health, 2004], although the evidence from some of the studies is conflicting [Duckitt, 2003].
Surgery for fibroids should be considered if there is no other explanation for infertility. It is essential for intracavity fibroids [Hart, 2003] and should be considered for intramural fibroids >5 cm in diameter, particularly when they are encroaching on the cavity [Kennedy, personal communication, 2004].
Surgery for varicoceles should not be offered, as it does not improve pregnancy rates [National Collaborating Centre for Women's and Children's Health, 2004].
Surgical correction of epididymal blockage in men with obstructive azoospermia is likely to restore fertility [National Collaborating Centre for Women's and Children's Health, 2004].
Intrauterine insemination (IUI) is the process, timed to coincide with ovulation, by which sperm is placed in the woman's uterus using a fine plastic tube. Low doses of ovary-stimulating hormones are usually also given, to maximize pregnancy rates. If IUI does not work, people move on to try IVF, or ICSI. Ovarian stimulation combined with IUI increases pregnancy rates in subfertile women with mild endometriosis [National Collaborating Centre for Women's and Children's Health, 2004].
Donor insemination (DI) is the insemination of sperm from a donor into a woman, via her vagina into the cervical canal or into the uterus itself (IUI). Sometimes low doses of ovary-stimulating hormones are used in conjunction with DI, with the aim of increasing pregnancy rates. DI should be considered as an option when the man has no or very few sperm on testicular biopsy or surgical extraction; has had a vasectomy, and reversal has failed or not been tried; or has an infectious disease such as HIV, or where there is a high risk of transmitting a genetic disorder to the offspring [National Collaborating Centre for Women's and Children's Health, 2004].
In vitro fertilization (IVF) involves retrieval of the egg(s), which is mixed with sperm and incubated for 2-3 days; the resultant embryo(s) is then injected into the uterus via the cervix. The Human Fertilisation and Embryology Authority recommends that only two embryos be implanted, to reduce the risk of multiple pregnancy [Braude and Rowell, 2003a; National Collaborating Centre for Women's and Children's Health, 2004].
Intracytoplasmic sperm injection (ICSI) involves an individual sperm being injected directly into the egg, to bypass natural barriers that prevent fertilization. ICSI is used for couples who have failed to achieve successful fertilization through conventional IVF, or where the quality or numbers of sperm is too low for normal IVF to be likely to succeed. ISCI is now the treatment of choice in severe male factor infertility [Kennedy, personal communication, 2004]. It may be worth re-referring to specialist clinics men with very low sperm counts who have been told in the past they cannot be helped [Chambers, 1999; Braude and Rowell, 2003a].
Oocyte donation involves stimulation of the donor's ovaries and collection of eggs, which are then fertilized by the recipient's husband's sperm. After 2-3 days the embryos are transferred to the uterus of the recipient via the cervix, following hormonal preparation of the endometrium. This method is suitable for women who have ovarian failure (either premature, or following radiotherapy or chemotherapy); who have had bilateral oophorectomy; where there is gonadal dysgenesis, including Turner's syndrome, or where there is a high risk of transmitting a genetic disorder. It is also used in certain cases of IVF failure [National Collaborating Centre for Women's and Children's Health, 2004].
Embryo donation. Couples who have had successful IVF or ICSI treatment may decide to donate their spare embryos to help other infertile couples [HFEA, 2004b].
Gamete intrafallopian transfer (GIFT) involves egg retrieval, mixing the eggs with the prepared sperm, and then injecting the eggs (maximum of three) with the sperm into the fallopian tube [Chambers, 1999; HFEA, 2004b]. There is insufficient evidence to recommend its use in preference to IVF in couples with unexplained infertility problems or male factor fertility problems [National Collaborating Centre for Women's and Children's Health, 2004].
Problems with assisted conception :
Ovulation hyperstimulation syndrome
Ovarian hyperstimulation syndrome (OHSS) generally develops if a woman has had an excessive response to gonadotrophins and has produced a large number of follicles (over 20). It is particularly severe in people with polycystic ovary syndrome who have been treated with human gonadotrophin-releasing hormone analogues. It can follow the use of clomifene in sensitive people, e.g. those with polycystic ovarian syndrome.
Early: within 1-5 days of human gonadotrophin injection, soon after egg collection and embryo transfer
Late: 7-14 days after embryo transfer when endogenous human chorionic gonadotrophin (HCG) rises after successful implantation
Symptoms and signs include:
Feeling unwell, nausea, vomiting
Abdominal pain, distension, or both caused by enlarged ovaries and acute ascites
Bowel disturbance--constipation or diarrhoea
Dark concentrated urine due to reduced renal perfusion and low urine output
Dyspnoea due to splinting of the diaphragm secondary to ascites or pleural effusion
Leg and vulval oedema
Seek urgent advice from a specialist unit if OHSS is suspected.
Ectopic pregnancy occurs in about 4% of pregnancies that occur after assisted conception. Heterotopic (one embryo in the uterus and one in the tube) pregnancy is extremely rare naturally (one in 30,000 pregnancies) but the rate may be as high as one in 100 pregnancies in women who have had assisted conception [Tal et al, 1996].
[Braude and Rowell, 2003b]
Counselling and information on infertility
It is important to involve both partners in all aspects of management. Discussion of wishes, plans, beliefs, and motives are important [Himmel et al, 1997].
Counselling should be made available to all infertile couples, and may cover these different aspects:
Implications of investigations and treatments
Emotional support for social and psychological issues such as stress
Help with ethical and legal issues, especially for assisted conception
Therapeutic counselling to help people accommodate the feelings they have about their infertility.
Information on infertility is often available locally and should be provided to the couple. National sources of up-to-date information include the Human Fertilisation and Embryology Authority (http://www.hfea.gov.uk/) and the patient organizations CHILD (http://www.child.org.uk/), ISSUE (http://www.issue.co.uk/) and BICA (http://www.bica.net/).
Anonymity of donors
Children born as a result of sperm, eggs, or embryos donated after 1 April 2005 will be able to access the identity of their donor when they reach the age of 18 years. This change in the regulation will not be retrospective. Anybody donating before April 2005 will remain anonymous.
Under existing regulations, when they reach the age of 18 years, people may ask the HFEA to confirm whether they were born as a result of donated sperm, eggs or embryos. Those intending to marry, including those who plan to do so before they reach the age of 18 years, may also ask whether the HFEA register shows that they are related to the person they intend to marry.
High-risk pregnancy is broadly defined as one in which the mother, fetus, or newborn is at or may possibly be at increased risk of morbidity or mortality before, during, or after delivery. Many factors are involved, including maternal health, obstetric history, and fetal disease.
Preconceptional evaluation and counseling of women of reproductive age has gained increasing acceptance as an important component of women's health.
MATERNAL ASSESSMENT FOR POTENTIAL FETAL OR PERINATAL RISK
INITIAL SCREENING :
A. MATERNAL AGE
Extremes of maternal age increase risks of maternal or fetal morbidity and mortality. Adolescents are at increased risk for preeclampsia-eclampsia, intrauterine growth restriction (IUGR), and maternal malnutrition.
Women 35 years of age or older at the time of delivery are at higher risk of pregnancy-induced hypertension, diabetes, and obesity as well as other medical conditions. Chromosomal abnormalities are also more common in infants born to older women, as will be discussed in detail later. An increased risk of cesarean section, preeclampsia, and placenta previa is noted in women with advanced maternal age.
B. MODALITY OF CONCEPTION
It is important to differentiate spontaneous pregnancy from that resulting from assisted reproductive technologies (ART). Use of ART increases the risks of multiple gestation, pregnancy-induced hypertension, and preterm delivery.
C. PAST MEDICAL HISTORY
Specific disease states may adversely affect the outcome of pregnancy for the mother or infant. Pregnancy itself may aggravate certain medical disorders and alleviate others.
D. FAMILY HISTORY
A detailed family history is helpful in determining any increased risk of heritable disease states (eg, Tay-Sachs, cystic fibrosis, sickle cell disease) which may affect the mother or fetus during the pregnancy or the fetus following delivery.
E. ETHNIC BACKGROUND
Population screening for certain inheritable genetic diseases is not cost effective due to the relative rarity of the gene in the general population. However, many genetic diseases affect certain ethnicities in disproportionate amounts, allowing those groups to be screened in a cost-effective way.
F. PAST OBSTETRIC HISTORY
1. Habitual abortion
A diagnosis of habitual abortion can be made after 3 or more consecutive spontaneous losses of a previable fetus. Habitual abortion is best investigated before another pregnancy occurs. If the patient is currently pregnant, as much of the work-up as possible should be performed.
Karyotype of abortus specimen
Survey for cervical and uterine anomalies
Connective tissue disease work-up
Screening for hormonal abnormalities (ie, hypothyroidism)
Acquired and inherited thrombophilias
Infectious disease evaluation of the genital tract
2. Previous stillbirth or neonatal death
A history of previous stillbirth or neonatal death should trigger an immediate investigation as to the conditions or circumstances surrounding the event. If the demise was the result of a nonrecurring event such as cord prolapse or traumatic injury, then the present pregnancy has a risk approaching a background risk. However, stillbirth or neonatal death may also suggest a cytogenetic abnormality, structural malformation syndrome, fetomaternal hemorrhage or thrombophilia (fetal or maternal), requiring a similar investigation as above.
3. Previous preterm delivery
The greater the number of preterm deliveries, as well as the degree of prematurity, the higher the risk at present for preterm delivery in the index pregnancy. Despite intense investigation, the incidence of preterm delivery has remained unchanged. Two-thirds of preterm deliveries occur near term (34 to 37 weeks), and these carry minimal fetal or neonatal morbidity. The remaining one-third of preterm deliveries accounts for nearly all of the perinatal morbidity and mortality. Approximately 50% of newborns born under 1000 grams suffer from intracranial hemorrhage, retinopathy of prematurity, or bronchopulmonary dysplasia, all of which carry significant long-term consequences. Approximately 40% of preterm delivery is due to spontaneous preterm delivery, another 40% is due to preterm rupture of membranes, and the remaining 20% is due to iatrogenic preterm delivery (eg, delivery due to preeclampsia or deteriorating fetal status). Spontaneous preterm labor is a complex process, but discrete pathophysiological processes have been identified (but may coexist): maternal and/or fetal stress, ascending genital tract infection, abruption (decidual hemorrhage), and uterine distension. Risk factors for preterm labor include prior history of preterm labor, multifetal pregnancy, vaginal bleeding in more than one trimester, in utero exposure to diethylstilbestrol (DES), uterine anomalies, incompetent cervix, and preterm labor in the index pregnancy. Screening for preterm labor in high-risk patients may include cervical length measurements by transvaginal sonography, fetal fibronectin of cervicovaginal secretions, and salivary estriol.
4. Rh isoimmunization or ABO incompatibility
Blood typing of both parents and maternal antibody screening should be performed at the initial prenatal visit. Women at risk for Rh(D) isoimmunization should be screened for anti-Rh(D) antibody at presentation, at 28 weeks gestation, and at delivery.
5. Previous preeclampsia-eclampsia
Previous preeclampsia-eclampsia increases the risk for hypertension in the current pregnancy, especially if there is underlying chronic hypertension or renal disease.
6. Previous infant with genetic disorder or congenital anomaly
A woman with a previously affected infant should be offered genetic counseling. Screening or testing is available for some defects using maternal blood samples (eg, alpha-fetoprotein; AFP), ultrasonography, amniocentesis, chorionic villus sampling, and DNA analysis.
7. Teratogen exposure
A teratogen is any substance, agent, or environmental factor that has an adverse affect on the developing fetus. Whereas malformations caused by teratogen exposure are relatively rare, knowledge of exposure can aid in the diagnosis and management.
Alcohol, anti-seizure medications (pheny-toin, valproic acid, etc), lithium, mercury, thalidomide, diethylstilbestrol (DES), coumadin, isotretinoin, etc.
b. Infectious agents
CMV, Listeria, rubella, toxo-plasmosis, varicella, Mycoplasma, etc.
It is commonly believed that medical diagnostic radiation delivering less than 0.05 Gy to the fetus has no teratogenic risk.
Uniform Perinatal Record
A consistent method of recordkeeping which is easily understandable from doctor to doctor and location to location is ideal to manage the high-risk patient. In the event of a transfer of care during a pregnancy, or a review of a previous pregnancy, having a coherent, accessible prenatal record helps avoid duplication of tests and helps to expedite diagnostic confirmation and the onset of treatment. Preprinted records such as American College of Obstetricians and Gynecologists (ACOG) forms provide uniform data for each patient and are helpful in diagnosis as well as in management decision making.
Every prenatal visit is an opportunity to not only screen for problems that may complicate the course of the pregnancy but also to anticipate any problems before they develop. Several factors should be evaluated at each visit.
A. VITAL SIGNS
Fever (> 100.4° F), even without other subjective complaints may be due to a wide source of infectious etiologies. Urinary, pulmonary, and hematological sources of the fever should be considered. Signs or symptoms of chorioamnionitis should be assessed, and if chorioamnionitis is suspected, amniocentesis for microscopy and culture should be considered. Depending on clinical correlation, delivery may be necessary. Very high fevers (> 103° F) may trigger preterm labor and may also have an adverse effect on the early development of the fetal central nervous system. Antipyretics may be necessary to lower the temperature.
Maternal tachycardia can be a sign of infection, anemia, or both. Isolated mild tachycardia (> 100 beats per minute [bpm]) should be evaluated and followed up. Moderate to severe tachycardia (> 120 bpm) needs immediate evaluation, including but not limited to a hemogram and an ECG.
C. BLOOD PRESSURE
The normal pattern of maternal blood pressure readings is for a decrease from baseline during the first trimester, reaching its nadir in the second trimester, and slightly rising in the third trimester, although not as high as the baseline levels. Repeated blood pressure readings of 140/90 mm Hg 6 hours apart or a rise of 30 mm Hg systolic pressure or 15 mm Hg diastolic pressure should be considered evidence of pregnancy-induced hypertension. Consideration of the patient's medical history, prepregnancy blood pressure, and gestational age should all be considered in forming a diagnosis and management strategy.
At the first prenatal visit, a clean-catch urine culture and sensitivity should be performed. Any growth should be treated with the appropriate antibiotics. At all subsequent visits, urine dipstick testing to screen for protein, glucose, leukocyte esterase, blood, or any combination of markers is useful in identifying patients with a change in their baseline urinary composition.
Screening Tests :
Screening tests are performed at the appropriate time during the pregnancy.
A. FASTER (FIRST AND SECOND TRIMESTER EVALUATION OF RISK FOR ANEUPLOIDY) TRIAL
Transvaginal sonography between 103/7 weeks and 136/7 weeks to visualize and measure nuchal translucency, along with serum measurements of PAPP-A and free β-hCG is currently being studied in several institutions throughout the United States as a screen for Down syndrome, as well as other aneuploidies and malformations.
B. MATERNAL SERUM ANALYTE TESTING
Frequently known as the “triple screen,” this test includes maternal serum alpha-fetoprotein (msAFP), β-hCG, and estriol. In some institutions, only the msAFP is used, while in other institutions a fourth test, inhibin, is included, making it a “quad test.” The usefulness of this screen is its ability to identify pregnancies at an increased risk for open neural tube defects, as well as for certain chromosomal abnormalities, especially trisomy 21 (75% sensitivity for Down syndrome detection). This test is effective at 15–19 weeks' gestation and can therefore identify an at-risk pregnancy in time to pursue more definitive diagnosis, if desired. It is important to note, however, that the triple screen is not a definitive test and that many positive screens have yielded normal fetuses and many abnormal fetuses have had normal screens.
C. DIABETES SCREEN
Routine screening consists of performing a glucose challenge test between 24 and 28 weeks. The test consists of a 50-g oral glucose load with a plasma glucose level drawn exactly 1 hour after. If the value is over 140 mg/dL, a more specific glucose tolerance test (GTT) should be performed. The GTT involves obtaining a fasting plasma glucose level, giving a 100-g oral glucose load, then drawing plasma levels at 1 hour, 2 hours, and 3 hours after the glucose load. A test is considered positive for gestational diabetes if two out of the four values are elevated.
A patient who is Rh-negative with a pregnancy fathered by an Rh-positive man should be screened for antibodies at the first prenatal visit and again at 24–28 weeks. If there continues to be no antibodies, Rhogam should be administered at 28 weeks to prevent sensitization of the mother during the last trimester and delivery. In the event of a previously isoimmunized patient, the typing and screening performed at the initial visit would detect antibodies, which are reported as a numerical titer. These titers should be followed every 4 weeks to assess for worsening isoimmunization. In the presence of worsening titers, follow-up with amniocentesis may be appropriate. Peak systolic velocity of the fetal middle cerebral artery as determined by sonographic Doppler evaluation has been demonstrated to correlate with degree of fetal anemia, allowing for noninterventional diagnosis and management of fetal isoimmunization; however, the definitive treatment is intrauterine fetal transfusion.
E. BETA HEMOLYTIC STREPTOCOCCUS
This is also known as the group B Streptococcus (GBS) test, and between 10% and 30% of pregnant women are colonized with GBS in the vaginal or rectal areas. Whereas they are usually asymptomatic colonizations, perinatal transmission can result in a severe and potentially fatal neonatal infection. Any documented GBS bacteriuria needs to be treated at the time of diagnosis, as well as intrapartum. Intrapartum antibiotic prophylaxis has been shown to decrease the risk of perinatal GBS transmission. There are two approaches to screening: Screen patients at 35–37 weeks' gestation and treat positive cultures with intrapartum antibiotics, or treat patients based on risk factors with intrapartum antibiotic prophylaxis.
Comprehensive fetal assessment begins in the first trimester with nuchal translucency and continues throughout the pregnancy into labor and delivery. Conceptually, antepartum testing in pregnancies at risk falls into one of two categories: assessment of prenatal diagnosis and assessment of fetal well-being.
A. ASSESSMENT OF PRENATAL DIAGNOSIS
Performed during all trimesters, the techniques used are diverse, and the information obtained varies according to the quality of imaging, depth of investigation, and gestational age of pregnancy.
Ultrasound has had a continuous evolution over the last 20 years, with better equipment being produced each year. Real-time sonography allows a 2-D image to demonstrate fetal anatomy, as well as characteristics such as fetal weight, movement, volume of amniotic fluid, and structural anomalies such as myomas or placenta previa which may affect the pregnancy. 3-D sonography allows volume to be ascertained, creating a three-dimensional appearing image on the 2-D screen, which assists in identifying certain anatomical anomalies. Most recently, 4-D machines have been developed, which produce a 3-D image in real time. As the machines become more technically advanced and the computers that run them become faster, the images obtained will continue to improve and push the boundaries of sonographic prenatal diagnosis.
Diagnostic ultrasonography is widely used in the assessment of the pregnancy and the fetus. It is not, however, the standard of care, nor is it recommended by ACOG for every pregnancy. The indications for ultrasonography are multiple and diverse, and the type and timing of the examination varies depending on the information being sought.
A basic ultrasound examination should provide such information as fetal number, presentation, documentation of fetal viability, placental location, and assessment of gestational age. A limited ultrasound examination is a goal-directed search for a suspected problem or finding. A limited ultrasound may be used for guidance during procedures such as amniocentesis or external cephalic version, assessment of fetal well being, or documentation of presentation or placental location intrapartum. A comprehensive ultrasound examination provides information on fetal anatomy, growth, anomalies, and physiologic complications.
Ultrasound evaluation of fetal anatomy may detect some major structural anomalies. Gross malformations such as anencephaly and hydrocephaly are more commonly diagnosed and rarely missed; however, more subtle anomalies such as facial clefts, diaphragmatic hernias, and neural tube defects are more commonly reported to have been missed by ultrasound. The basic fetal anatomy survey should include visualization of the cerebral ventricles, four-chamber view of the heart, and examination of the spine, stomach, urinary bladder, umbilical cord insertion site, and renal region. Any indication of an anomaly should be followed by a more comprehensive sonogram. Typically, the fetal anatomic survey is performed at 17–20 weeks; however, there is controversy surrounding the potential benefits of an earlier sonogram at 14–16 weeks using the transvaginal probe. The earlier scan allows earlier detection of anomalies that are almost always present by the second trimester, as well as allowing greater detailed viewing of the fetal anatomy by using the higher-resolution vaginal transducers.
2. Aneuploidy screening
Multiple sonographic markers for aneuploidy have been identified. The presence of single or multiple markers adjusts the patient's age-related risk of aneuploidy based on the particular markers present. Such sonographic findings include, but are not limited to:
Echogenic intracardiac focus
Choroid plexus cysts
Hypomineralization of the fifth digit of the fetal hand
Amniocentesis is frequently performed under the guidance of ultrasonography. A needle is inserted transcutaneously through the abdominal wall into the amniotic cavity, and fluid is removed. There are many uses for this amniotic fluid, including cytology for detection of infection, alpha-fetoprotein evaluation for neural tube defect assessment, assessment of fetal lung maturity (which will be discussed later in the chapter), and the most common indication of cytogenetic analysis. In this case, amniocentesis is often performed between 15 and 20 weeks' gestation and fetal cells from the amniotic fluid are obtained. Risks associated with the procedure are considered to be very low, with the risk of abortion as a result of amniocentesis considered to be between 1 in 200 to 1 in 450 amniocenteses.
4. Chorionic villus sampling
Chorionic villus sampling (CVS) is an alternative to amniocentesis. It is performed between 10 and 12 weeks' gestation, and can be performed either transcervically or transabdominally. CVS is also performed under sonographic guidance, with the passing of a sterile catheter or needle into the placental site. Chorionic villi are aspirated and undergo cytogenetic analysis. The benefit of CVS over amniocentesis is its availability earlier in pregnancy; however, the rate of abortion is higher—as high as 1%. One disadvantage
of CVS is that unlike amniocentesis, it does not allow diagnosis of neural tube defects.
5. Fetal blood sampling
Also referred to as cordocentesis or percutaneous umbilical blood sampling (PUBS), this is an option for chromosomal or metabolic analysis of the fetus. Benefits of the procedure include a rapid result turnaround rate and the ability to perform the procedure in the second and third trimester. Intravascular access to the fetus is useful for the assessment and treatment of certain fetal conditions such as Rh sensitization and alloimmune thrombocytopenia. There is a higher risk of fetal death, however, when compared to the other methods. Fetal loss rates are approximately 2%, but can vary depending on the fetal condition involved.
B. ASSESSMENT OF FETAL WELL-BEING
1. Fetal monitoring techniques
Assessment of fetal status can be performed using a wide variety of techniques.
a. External fetal monitoring
The external measurement of the fetal heart rate is done by using a continuous beam of ultrasound waves focused on the fetal heart. This ultrasound monitor utilizes Doppler effects to sample the frequency of moving fetal heart valves and the atrial and the ventricular systole. The complex received signal wave is then peak detected and entered into the heart rate monitor. The computer averages several consecutive frequencies, which helps minimize artifact, before the signal is displayed and printed. This process of averaging is called autocorrelation, and produces a fetal heart rate pattern which closely resembles that derived from a fetal ECG, although there is more baseline variability inherent in this method.
b. Internal fetal monitoring
The internal measurement of the fetal heart rate is an invasive procedure, utilizing an electrode attached to the fetal scalp. A bipolar spiral electrode is placed transcervically and penetrates the fetal scalp. A reference electrode is placed on the maternal thigh to eliminate electrical interference. The fetal ECG is detected, and the R wave is the signal used for peak detection and for counting. This signal is very clear, and allows accurate beat-to-beat and baseline variability to be measured. Artifact is kept to a minimum, and there is little need for autocorrelation.
c. Sonographic fetal monitoring
There have been reports of a number of sonographically related surveillance techniques for fetal status published in the literature. Such testing techniques as biophysical profile and Doppler velocimetry have been extensively studied and widely used for antepartum evaluation. Doppler velocimetry is a noninvasive technique based on vascular impedance. Most often, the umbilical artery is utilized for this purpose. Both the peak values as well as the actual waveform can be utilized to identify abnormally growing fetuses, or fetuses at risk of cardiac failure or other adverse outcome. Most of the benefit is seen in growth-restricted pregnancies, and use for generalized surveillance is not recommended. Biophysical profile consists of fetal heart rate evaluation combined with sonographically assessed parameters of fetal well being, including fetal breathing movements, fine motor movement, gross fetal tone, and amniotic fluid volume.
2. Fetal heart rate interpretation
a. Antepartum fetal surveillance
In determining which patients should have antepartum fetal surveillance, a major factor to consider is the lack of evidence that any routine surveillance method results in a decreased risk of fetal death. Therefore, we generally begin monitoring in pregnancies in which the risks of fetal demise are known to be increased. These can include maternal conditions such as antiphospholipid syndrome, lupus, diabetes, or other maternal medical problems. They can also include pregnancy-related conditions such as preeclampsia, IUGR, multiple gestation, poor obstetrical history, or postterm pregnancy.
Antepartum surveillance should include a nonstress test (NST) as a minimum. The addition of sonographic monitoring is common, most often as some variant of the biophysical profile. The criteria for the NST are: baseline between 120 and 160 bpm, the presence of periodic accelerations (ie, two accelerations in 20 minutes) of fetal heart rate of 15 bpm over baseline for 15 seconds, the absence of decelerations of the fetal heart rate, and the subjective assessment of variability of the fetal heart rate. In the case of a nonreassuring NST, further evaluation or delivery depend on the clinical context. In a patient at term, delivery is warranted. Near term, determination of fetal lung maturity can be considered. Remote from term poses a more challenging dilemma to the clinician. If resuscitative efforts are not successful in restoring reactivity to the NST, ancillary tests or testing techniques may prove useful in avoiding a premature iatrogenic delivery for nonreassuring fetal heart rate patterns, since the false-positive rate may be as high as 50–60%.
C. ANCILLARY TESTS
1. Vibroacoustic stimulation
An auditory source, often an artificial larynx, is placed on the maternal abdomen. A short burst of sound is delivered to the fetus. This has proven successful in shortening the duration needed for the test to show reactivity, without compromising the predictive value of the absence of acidosis with a reactive NST.
2. Fetal scalp stimulation
The presence of an acceleration after a vaginal exam where the examiner stimulates
the fetal vertex with the examining finger confirms the absence of acidosis (pH > 7.2).
3. Oxytocin challenge test
This may be used to elicit a confirmatory abnormal fetal heart rate response, with one report showing a better correlation with adverse outcome than the NST alone. Other studies, however, have demonstrated no improvement in predicting morbidity over an NST. This is performed by intravenous infusion of dilute oxytocin until three contractions occur in 10 minutes. A positive test indicates decreased fetal reserve, with a 20–40% incidence of abnormal fetal heart rate (FHR) patterns in labor. A positive test is the presence of a late deceleration after each of the three contractions, a negative test shows no decelerations, and anything else is equivocal. Repetitive variable decelerations are termed “suspicious” and are associated with abnormal FHR patterns in labor, particularly in postterm gestations.
Fetal Maturity Tests
Indications for assessing fetal lung maturity—The American College of Obstetricians and Gynecologists has recommended that fetal pulmonary maturity should be confirmed before elective delivery at less than 39 weeks' gestation unless fetal maturity can be inferred from any of these criteria: Fetal heart tones have been documented for 20 weeks by nonelectronic fetoscope or for 30 weeks by Doppler; and 36 weeks have elapsed since a serum or urine hCG-based pregnancy test was reported to be positive.
A. LECITHIN:SPHINGOMYELIN RATIO
The lecithin:sphingomyelin (L:S) ratio for assessment of fetal pulmonary maturity was first introduced by Gluck and colleagues in 1971. The test depends upon outward flow of pulmonary secretions from the lungs into the amniotic fluid, thereby changing the phospholipid composition of the latter and permitting measurement of the ratio of lecithin to sphingomyelin in a sample of amniotic fluid. The concentrations of these two substances are approximately equal until 32–33 weeks of gestation, at which time the concentration of lecithin begins to increase significantly while the sphingomyelin concentration remains about the same. The measurement of sphingomyelin serves as a constant comparison for control of the relative increases in lecithin because the volume of amniotic fluid cannot be accurately measured clinically. Determination of the L:S ratio involves thin-layer chromatography after organic solvent extraction. It is a difficult test to perform and interpret; care at each step of sample handling is critical for consistent results. The sample should be kept on ice or refrigerated if transport to a laboratory is required. Improper storage conditions can change the L:S ratio since amniotic fluid contains enzymes that can be affected by temperature. The amniotic fluid samples must be mixed well. The presence of blood or meconium can interfere with test interpretation. Bloody samples give false information due to the presence of sphingomyelin in blood and decreased extraction of lecithin by cold acetone techniques in the presence of red blood cells. Therefore, if blood or other particulate matter is present in the amniotic fluid sample, a low-speed, short centrifugation can be used to remove the cellular component.
Interpretation of the results should be carried out with consideration of the individual clinical circumstances. For example, some physicians require a higher L:S ratio for confirmation of fetal pulmonary maturity in pregnancies complicated by isoimmunization or diabetes mellitus.
A threshold value for prediction of lung maturity should be calculated in individual centers by correlation with clinical outcome, because the variation within and between laboratories can be considerable. Empirically, the risk of respiratory distress syndrome (RDS) is exceedingly low when the L:S ratio is greater than 2.0.
Phosphatidylglycerol (PG) is a minor constituent of surfactant. It begins to increase appreciably in amniotic fluid several weeks after the rise in lecithin. Its presence is more indicative of fetal lung maturity as PG enhances the spread of phospholipids on the alveoli; thus, its presence indicates a more advanced state of fetal lung development and function.
PG determination is not generally affected by blood, meconium, or other contaminants; its ability to predict pulmonary maturity is the same whether or not contam-ination is present. This is an advantage for assessing fetal lung maturity status since these substances are commonly found in amniotic fluid.
PG testing is performed by thin-layer chromatography (as for the L:S measurement), so it may be determined alone or in conjunction with L:S testing. It can be reported qualitatively as positive or negative, where positive represents an exceedingly low risk of RDS, or in a quantitative fashion, in which a value ≥ 0.3 is associated with a minimal rate of respiratory distress.
C. FOAM STABILITY INDEX
The foam stability index (FSI) is a rapid predictor of fetal lung maturity and is based upon the ability of surfactant to generate stable foam in the presence of ethanol. Ethanol is added to a sample of amniotic fluid to eliminate the effects of nonsurfactant factors on foam formation. The mixture is shaken and will demonstrate generation of a stable ring of foam if surfactant is present in the amniotic fluid. The FSI is calculated
by utilizing serial dilutions of ethanol to quantitate the amount of surfactant present.
Amniotic fluid samples should not be collected in silicone tubes when this test is planned, as the silicone will produce “false foam.” The discriminating value indicative of lung maturity is usually set at ≥ 47. A positive result virtually excludes the risk of RDS; however, a negative test often occurs in the presence of mature lungs. The presence of blood or meconium interferes with results of the FSI.
D. FLUORESCENCE POLARIZATION
The fluorescence polarization test uses polarized light to quantitate the competitive binding of a probe to both albumin and surfactant in amniotic fluid; thus, it is a true direct measurement of surfactant concentration. It reflects the ratio of surfactant to albumin and is measured by an automatic analyzer, such as the TDx-FLM. An elevated ratio has been correlated with the presence of fetal lung maturity; the threshold for maturity is 55 mg of surfactant per gram of albumin.
Evaluation of the accuracy of TDx measurements has also been studied, specifically in diabetic patients. Despite initial evidence that higher cutoffs were required for diabetics, it is currently believed that the same cutoff for lung maturity can be used for both nondiabetic and diabetic patients.
The accuracy of this test compares favorably with the well-established L:S and PG tests. Blood and meconium contamination interfere with interpretation, although the degree or direction of the interference is unclear. There is insufficient evidence regarding the accuracy of this test for determination of fetal lung maturity in vaginally-collected specimens.
A disadvantage to the TDx-FLM method is the large quantification scale. Values greater than 55 are regarded as mature; however, values of 35–55 are considered borderline. In addition, there is controversy as to whether gestational age should be used in interpreting the TDx for determining the likelihood of RDS. In one report, higher threshold values were needed at earlier gestational ages to determine lung maturity and lower thresholds were required at later gestational ages.
Intrapartum Fetal Surveillance
Assessment of the fetus in labor is a challenging task. Certain techniques that were useful in the antepartum period are no longer accurate, and certain new techniques have become available. With the presence of contractions, fetal heart rate monitoring is no longer a nonstress test. Fetal heart rate assessment is still the initial test of choice. Continuous fetal monitoring and intermittent auscultation have been extensively reviewed, and the evidence does not support one over the other for routine obstetric care. Several reports suggest that continuous monitoring results in higher operative delivery rates without an associated neonatal benefit. For the present, the controversy over routine FHR monitoring remains, but the clinical practice is nearly universal for continuous electronic monitoring of the FHR in hospitals and many birthing centers.
In the intrapartum period, access to the fetus allows for further evaluation in the face of a nonreassuring FHR tracing. Direct measurement of the physiologic status of the fetus is possible after adequate cervical dilation and rupture of the membranes.
A. ANCILLARY TESTS
1. Fetal scalp blood sampling
Capillary blood collected from the fetal scalp typically has a pH lower than arterial blood. A pH of 7.20 was initially believed to be the critical value to identify serious fetal stress and an increase in the incidence of low Apgar scores. However, there is much debate over the accuracy of scalp pH in predicting fetal distress with subsequent neurologic sequelae. Continuous scalp pH during labor was highly successful in defining abnormal FHR patterns associated with acidosis, although the advanced technical skill and expense prohibited widespread use. In fact, despite the correlation with FHR, fetal scalp pH is no longer used in many institutions. The only proven benefits reported for scalp pH testing were demonstration of adverse neurologic outcome with pH < 7.1, and fewer cesarean sections for fetal distress.
2. Fetal lactate levels
Collected in the same fashion as scalp pH, lactate levels demonstrated a higher predictive value than pH as markers of neurologic disability.
3. Fetal pulse oximetry
This has been studied over the past 10 years. Controversy exists over its potential clinical value. There is debate about its accuracy in correlating with acidemia. Studies have demonstrated no benefit in relation to FHR patterns, or in detecting neurologically-compromised fetuses. A recent report demonstrating a reduction in the rate of cesarean section for a diagnosis of distress, without an actual decrease in the incidence of cesareans compared with the control group, raised questions about the usefulness of the test, since it was hoped that it could reduce the cesarean section rate in a manner similar to scalp pH and lactate assays. Clearly, more studies need to be initiated to demonstrate a clear benefit to this test.
B. FETAL HEART RATE PATTERNS
1. Reassuring fetal heart rate patterns
Slight deviations from the normal baseline of 120–160 bpm and some periodic changes are innocuous in the continuum of the fetal heart rate pattern. Early decelerations and bradycardia of 100–119 bpm are believed to be vagally mediated due to fetal head compression, and are not associated with fetal acidosis or poor neonatal outcome. Certain cardiac arrhythmias also pose no threat to the fetus while the fetal heart rate pattern deviates from what is considered “normal.” In fact, the majority of fetal arrhythmias are benign and spontaneously convert to normal sinus rhythm by 24 hours postpartum. Persistent tachyarrythmias are well tolerated, but may proceed to fetal hydrops if present for many hours to days. Persistent bradyarrhythmias are often associated with fetal heart disease, but are seldom associated with hypoxia or acidosis in fetal life or labor. Accelerations and variable decelerations of variable shape and timing are indicative of a normal autonomic nervous system.
2. Nonreassuring fetal heart rate patterns
This category is of more concern to the clinician, and while there is still evidence that the fetus is not acidotic, continuation or worsening of the clinical situation may result in fetal distress. Late deceleration is a smooth fall in the fetal heart rate beginning after the contraction has started, and ending after the contraction has ended. They are associated with a fall in fetal pH and a potential for perinatal morbidity and mortality. Another nonreassuring pattern is the sinusoidal heart rate. It is best defined as a pattern of regular variability resembling a sine wave with a fixed period of 3–5 cycles per minute and an amplitude of 5–40 bpm. The mechanism for the sinusoidal pattern is believed to be a response to moderate fetal hypoxemia, including secondary to fetal anemia. It was previously thought to carry a high perinatal mortality. However, follow-up with serial scalp pH has been successfully performed with no adverse outcome. The significance of sinusoidal heart rate patterns depends on the clinical setting. Variable decelerations may be divided into categories, with the deciding characteristic being the onset and the timing of the return to baseline. If a variable deceleration, no matter how deep, does not have a late component, then the pattern is benign and at most is mild cord compression not associated with acidosis or low Apgar scores. When there is a late recovery, the fetal pH falls progressively during the period of deceleration.
3. Fetal distress patterns
Considerable confusion surrounds the diagnosis of fetal distress. Fetal distress should be defined operationally as a pathological condition of the fetus that is likely to cause fetal or neonatal death or damage to the newborn if left uncorrected for a period of greater than 1 hour. It is often, but not always, associated with fetal acidemia and hypoxemia. These metabolic changes are highly correlated with a decompensated fetal homeostasis, but not necessarily with all nonreassuring .
FHR patterns. There are numerous causes and multiple factors associated with fetal distress; however, only a few fetal heart rate patterns are associated with true fetal distress, including:
a. Undulating baseline
Alternating tachycardia and bradycardia with wide swings, often with reduced variability in between.
b. Severe bradycardia
Fetal heart rate below 100 bpm for a prolonged period of time of at least 10 minutes.
c. Tachycardia with diminished variability unrelated to drugs
d. Tachycardia associated with additional nonreassuring periodic patterns such as late decelerations or variable decelerations with late recovery
With careful interpretation, FHR patterns can be a useful screening test for fetal acidemia and hypoxemia. The monitoring and interpretation of the fetal heart rate is ideally used as a screening tool. The presence of a reassuring FHR pattern is just that, reassuring that there is no fetal acidemia at that time. The absence of a reassuring tracing is not necessarily problematic, and ancillary testing can be performed to eliminate false positives. However, it must be remembered that a given segment of FHR monitoring is a single point in time. Pregnancy and labor are ongoing dynamic states. Maternal and fetal conditions and the processes of gestation, especially labor, are stresses which challenge fetal homeostasis. Fetal stress may be manifested in the FHR pattern, while the fetus remains compensated. The clinician must discriminate between stress and distress, using interpretation and ancillary testing. All monitoring techniques are to be ultimately used as supplements to clinical judgment, to obtain the best outcome of pregnancy.
Assessing pregnancy to determine risk as well as carefully monitoring pregnancies with a recognized risk begins early in the gestation. Preconceptual counseling of patients with known medical or genetic disorders helps to optimize outcomes. Early and frequent prenatal care allow the care provider to screen his or her patient population to identify pregnancies at risk and act accordingly. Additionally, pregnancies identified as complicated by one or more issues can be followed by assortments of maternal and fetal surveillance techniques to maximize therapeutic treatment.
As technology advances and our ability to both diagnose and treat improve, the methods for assessment and care of the pregnancy at risk will be a constantly changing field.