ABSTRACT
Mild polyhydramnios was defined sonographically as an amniotic fluid index of 24.1-39.9 during fetal biophysical testing. All subjects had singleton gestations not complicated by conditions known to predispose to polyhydramnios. Mild polyhydramnios was diagnosed in 48 of 279 patients [8.2%] undergoing fetal testing at 26-42 gestational weeks. Premature delivery, intrapartum complications, and neonatal depression were no more frequent in the pregnancies complicated by mild, unexplained polyhydramnios than in a comparable control group with normal fluid volume. The mild polyhydramnios group showed a significantly higher incidence of birth weight greater than 4000 g than did the control group [18.66 versus 8.6%, P <0.05]. It was concluded that mild idiopathic polyhydramnios in late gestation is relatively common. Except for a higher incidence of large for gestational age fetuses, this condition by itself is not associated with an increased risk of adverse perinatal outcomes