Polyhydramnios is an excess of amniotic fluid, which is normally 500-1500ml at term. It is diagnosed clinically or via ultrasound. Causes include maternal diabetes or fetal abnormalities. Management depends on if the excess fluid is acute or chronic, and involves bed rest, ultrasound, draining fluid via needle if fetus is normal, or inducing labor. Oligohydramnios is the opposite condition of low amniotic fluid which can be associated with fetal abnormalities and complications like preterm labor and death.

1.  Polyhydramnios
 Definition: an excess of amniotic fluid detected
clinically. The range of normal volumes of fluid
present is wide and varies with the duration of
pregnancy.
Average values for amniotic fluid are:
12 weeks: 50ml;
24 weeks: 500ml;
36 weeks: 1000ml;
 The normal range at term in a singleton
pregnancy is large—500–1500ml.
 Diagnosis:- This is either clinical or by simple
ultrasound. Other methods of measuring
amniotic fluid in situ are too complex for routine
use and often unreliable.
 History
Tenseness of abdomen.
Unable to lie comfortably in any position.
Dyspnoea, indigestion, piles and varicose veins.
Decreased sensation of fetal movements.
 Examination
 Increased symphysio-fundal height.
 Very tense, cystic uterus bigger than
maturity (like a balloon filled with water).
 Difficult to feel any fetal parts.

2.  Investigations
Ultrasound. The deepest column >8cm or the
amniotic
fluid index is greater than the 95th centile.
 Differential diagnosis
 Twins: laxer feel to uterus and too many
fetal parts felt.
 Ovarian cyst: uterus displaced to one
side in later
 pregnancy.
 Full bladder.
 All are resolved by ultrasound
examination.
Associations
 MATERNAL
• Diabetes.
 FETAL
• Congenital abnormality; anencephaly;
 meningomyelocoele; upper alimentary atresia
e.g.
 tracheoesophageal fistula.
• Twins (particularly monozygotic).
 Clinical course
 ACUTE

3. • Painful with tense uterus and oedematous
abdominal wall.
• Primiparous.
• Pre-eclampsia.
• Often early (22–32 weeks’ gestation).
 CHRONIC
• Slower onset.
• Uncomfortable rather than painful.
• Last weeks of pregnancy.
 Management
 ACUTE
1 Bed rest.
2 Ultrasound to rule out twins or abnormality.
3 Release fluid from uterus.
If fetus normal: through abdominal wall with
 narrow-bore needle. Drain fluid off slowly until
the woman is comfortable (500–1000ml over 4–
8 hours).
• If fetus abnormal and viable—consider
induction.
 If not viable—paracentesis.
 CHRONIC
1 Bed rest.
2 Ultrasound to rule out twins and fetal abnormality.
3 Glucose tolerance test.

4. 4 Sedation if very painful.Treat underlying maternal
condition.
5 If fetus normal, induce labour when indicated by
fetal state not because of the polyhydramnios. Watch
for uterine dysfunction and postpartum haemorrhage
(PPH) after labour.
 Oligohydramnios
 A lack of amniotic fluid, a much rarer
 condition.
 Diagnosis
• Uterus is small for dates (early).
• Uterus feels full of fetus (later).
• Ultrasound shows reduced amniotic fluid
index
 (<2cm columns).
 Fetal associations
• Adhesions from fetal skin to amnion.
• Renal agenesis.
• Asymmetrical SGA.
 Clinical course
• Labour often preterm.
• High fetal death rate.
• High rate of fetal