gynecology and obstetrics
Oligohydramnios
Key Points
Oligohydramnios is amniotic fluid volume that is less than expected for gestational age. Oligohydramnios can be caused by uteroplacental insufficiency, drugs, fetal abnormalities, or rupture of membranes. It can cause problems in the fetus (eg, growth restriction, limb contractures, death, delayed lung maturation, inability to tolerate labor). If oligohydramnios is suspected, determine the amniotic fluid index or single deepest pocket and test for possible causes (including doing a comprehensive ultrasonographic evaluation). Do ultrasonography a least once every 4 weeks, and consider fetal monitoring at least once a week and delivery at 36 to 37 weeks/6 days or at diagnosis if diagnosed at ≥ 37 weeks (although optimal time for delivery varies based on clinical context). 