Monday, December 31, 2007
Diagnosis of Pregnancy
(I) THE FIRST TRIMESTER (0-12 WEEKS)
(A) Symptoms:
1.Amenorrhoea : sudden cessation of a previously regular menstruation is the most
common symptom denoting pregnancy. However, pregnancy may occur during
lactational amenorrhoea. On the other hand, bleeding may occur early in
pregnancy as in threatened abortion. Slight bleeding may occur also at the
expected time of menstruation in the first 12 weeks of pregnancy but never
afterwards due to separation of parts of the decidua vera.
2.Morning sickness: nausea with or without vomiting commences in the morning.
It usually appears about 6 weeks after onset of the last menstrual period and
usually disappears 6-12 weeks later.
3.Frequency of micturition: due to congestion and pressure on the bladder and
disappear after the first trimester to reappear again near the end of pregnancy when
the foetal head descends into the maternal pelvis.
4.Breast 4. symptoms: as enlargement, sensation of fullness, tingling and tenderness.
5. Appetite changes and sleepiness.
(B) Signs:
(I)Breast signs:
1. Increase in size and vascularity.
2. Increase pigmentation of the nipple and primary areola.
3. Appearance of the secondary areola.
4. Montgomery’s follicles.
5. Expression of colostrum.
6. Breast signs are diagnostic only in primigravidae. In multigravidae , it may be due
to the previous pregnancies
.
(II) Uterine signs:
1. The uterus becomes enlarged, globular and soft.
2. Palmer's sign: uterine contractions felt during bimanual examination.
3. Hegar's sign: during bimanual examination, the two fingers in the anterior fornix
can be approximated to fingers of the abdominal hand behind the uterus due to
softening of the lower part of the uterus and its emptiness. This sign can be elicited
between 6-10weeks but not after as the growing conception will fill the whole
uterine cavity.
(III) Cervix : soft, hypertrophied and violet.
(IV) Vagina: violet, moist, warm with increased acidity.
(C) Investigations:
(I) Pregnancy tests:
These depend on presence of human chorionic gonadotrophin (hCG) in maternal serum and urine.
1- Urine pregnancy tests :
i- Agglutination Test: Latex particles, or sheep erythrocyte (tube) coated with anti-hCG.
ii- Agglutination Inhibition Tests
iii- Dip stick
Rapid and simple tests based on enzyme-labelled monoclonal antibodies assay can detect low level of
hCG in urine.
Causes of false positive results:
1. Proteinuria.
2. Haematuria.
3. At time of ovulation (cross reaction with LH).
4. HCG injection for infertility treatment within the previous 30 days.
5. Thyrotoxicosis (high TSH).
6. Premature menopause (high LH & FSH).
7. Early days after delivery or abortion.
8. Trophoblastic diseases.
9. hCG secreting tumours.
Causes of false negative results:
1. Missed abortion.
2. Ectopic pregnancy.
3. Too early pregnancy.
4. Urine stored too long in room temperature.
5. Interfering medications.
2- Serum pregnancy tests:
(i) Radioimmunoassay of b -subunit of hCG.
(ii) Radio receptor assay.
3- Enzyme- linked immunosorbent assay (ELISA).
can be used for urine and serum.
The pregnancy test becomes negative about:
l one week after labour,
l 2 weeks after abortion, and
l 4 weeks after evacuation of vesicular mole.
Uses of pregnancy test:
1. Diagnosis of pregnancy.
2. Diagnosis of foetal death.
3. Diagnosis of ectopic pregnancy.
4. Diagnosis and follow up of gestational trophoblastic diseases.
(II) Ultrasonography:
Gestational sac can be detected after 4-5 weeks of amenorrhoea. Foetal heart pulsation can be detected
as early as 7 weeks.
(II) THE SECOND TRIMESTER (13-28 WEEKS)
(A) Symptoms:
1. Amenorrhoea.
2. Morning sickness and urinary symptoms decrease.
3.Quickening : The first sensation of the foetal movement by the mother, occurs at
18-20 weeks in primigravida and at 16-18 weeks in multiparas.
4. Abdominal enlargement.
(B) Signs:
1. Breast signs: become more manifested.
2. Skin signs : Cloasma, linea nigra and striae gravidarum appear.
3. Uterine signs:
i-The uterus is felt abdominally.
ii-Braxton Hick's contractions: intermittent painless contractions can be felt
by abdominal examination.
4-Foetal signs:
i- Internal ballottement: can be elicited at 16 weeks by a push
to the foetal parts with the two fingers through the anterior
fornix.
ii- External ballottement: can be elicited at 20 weeks by a push
to the foetal parts with one hand abdominally and the other
hand receiving the impulse.
iii- Palpation of foetal parts and movement: by the obstetrician
at 20 weeks.
iv- Foetal heart sound: can be auscultated at 20-24 weeks by the
Pinard's stethoscope.
v- Umbilical (funic) souffle: A murmur with the same rate of
FHS due to rush of blood in the umbilical arteries. It is
occasionally detected when a loop of the cord lies below the
stethoscope.
(C) Investigations in doubtful cases.
1. Pregnancy tests.
2. Ultrasonography.
X-ray: It shows the foetal skeleton starting from the 16th week of pregnancy. It has
3.been replaced by ultrasonography due to the following hazards:
i- Teratogenic effects particularly before 10 weeks.
ii- Chromosomal changes in the foetal gonads leading to
genetic disorders in the following generations.
iii- Subsequent leukaemia in childhood.
(III) THE THIRD TRIMESTER (29-40 WEEKS)
All signs of pregnancy become more evident. Pregnancy tests are positive, sonar and X-ray are
diagnostic.
Sure Signs of Pregnancy:
1. Palpation of foetal parts.
2. Palpation of foetal movements.
3. Auscultation of foetal heart sounds.
4. The occasional auscultation of the umbilical (funic) souffle.
5. Detection of foetal skeleton by X-ray.
6. Ultrasonographic detection of foetal parts, movements and /or heart movements.
Differential Diagnosis of Pregnancy:
(A) Early pregnancy:
(I) Causes of amenorrhoea.
(II) Causes of symmetrically enlarged uterus:
1- Myoma.
2- Adenomyosis.
3- Pyometra.
4- Haematometra.
5-Metropathia haemorrhagica.
(III) Pelvi-abdominal swellings:
1- Ovarian swellings.
2- Tubal swellings.
3- Pelvic haematocele.
4- Full bladder.
(B) Late pregnancy:
1- Myomas.
2- Ovarian neoplasm.
3- Ascitis.
4- Pseudocyesis.
5- Other causes of pelvi-abdominal mass.
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1 comments:
safety of x ray in pregnancy
common drugs used in pregnancy (common cold, fever,diarea, peptic ulcer, hypertension) what use , not use
thanks dr alaa
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