ABSTRACT
Oligohydramnios occurs in 0.5–%1% of pregnancies. The diagnosis is usually made subjectively. Amniotic fluid is mainly produced by fetal urine. Before 16 weeks the placenta contributes significantly and therefore oligohydramnios is unusual before mid-gestation, with the exception of rupture of membranes (ROM). A lack of amniotic fluid can lead to pulmonary hypoplasia due to compression of the chest and abdomen and limitation of movement of the diaphragm, and after birth this leads to death from severe respiratory insufficiency. Treatment of pre-term ROM at less than 26 weeks of gestation with serial amnioinfusion has been reported as improving the outcome in some cases, but this requires further evaluation. A randomized controlled trial reported that the chance of newborn babies surviving with normal renal function is very low irrespective of whether vesico-amniotic shunting is done.
