Amniotic Fluid Volume Disorders
There are two chief abnormalities of amniotic fluid:
The amount of liquor amni exceeds to cause abnormalities in pregnancy (more than two litres). The incidence is 0.5 to 1%.
Polyhydramnios is a medical condition describing an excess of amniotic fluid in the amniotic sac.
- The exact cause is still speculative.
- Gastrointestinal abnormalities such as Oesophageal atresia and Duodenal atresia, anencephaly, facial cleft, neck masses, Tracheoesophageal fistula and Diaphragmatic hernia.
- Bochdalek hernia is one of two forms of a congenital diaphragmatic hernia in which the pleuro-peritoneal membranes will fail to develop and seal the pericardia-peritoneal canals.
- Fatal renal disorder that result in increase urine production during pregnancy. such s in antenatal Bartter syndrome.
- Neurological abnormalities such as Anencephaly, which impair the swallowing reflex.
- Chromosomal abnormalities such as Down syndrome and Edwards syndrome.
- Skeletal dysplasia or dwarfism.
- Sacrococcygeal teratoma.
- Multifetal pregnancy and maternal diabetes mellitus.
- Baby develop an infection
Depending on the speed of onset of polyhydramnios it may be chronic polyhydramnios and acute polyhydramnios.
1. Chronic Polyhydramnios
It is common and develops slowly in late pregnancy.
2. Acute Polyhydramnios
It is very rare. Onset is sudden; the uterus reaches the xiphisternum in about 3 or 4 days.
- Marked enlargement of abdomen, dyspnoea, palpitations difficulty in walking, pain abdomen, oedema of legs and vomiting suggestive of pre-eclampsia.
- Difficulty with bowel movements (Constipation)
- Abdominal examination. The uterus size is large for the corresponding period of gestation. The abdominal skin is tense, thin, shiny with large straie, fluid thrill can be obtained in all direction and foetal parts cannot be palpated.
- Enlargement of vulva
- Swelling of leg, thigh, hip, ankle and/or foot
- Investigation will include ultrasonography, blood for sugar and amniotic fluid testing for alpha foeto proteins.
- Pre-term labour
- Uterine inertia
- Post-partum haemorrhage
- The cause and degree of polyhydramnios is assessed.
- The presence of foetal abnormality will become a base in choosing the mode of timing of delivery.
- Bed rest is promoted extra salt and excess drinks are restricted. Comfort measures to reduce discomfort caused by overdistended uterus.
- Upright position will help to relieve any dyspnoea and antacids be given to relieve heartburn and nausea.
- Measures to combat post-partum haemorrhage and shock should be taken.
- The baby should be carefully examined for any abnormality and the patency of oesophagus ascertained by passing nasogastric tube. If pregnancy is less than 37 weeks efforts are made to continue pregnancy by amniocentesis.
- Slow decompression is done but the fluid may recur again and in 50% of cases premature labour starts.
- If pregnancy is more than 37 weeks the labour is induced. In case of foetal anomaly termination of pregnancy is done.