Delivery mode and perinatal outcomes after diagnosis of oligohydramnios at term in China

Objective: The purpose of this study is to assess the incidence of oligohydramnios at term and evaluate whether the mode of delivery in patients with oligohydramnios influences perinatal outcomes in China.Methods: A cross-sectional survey of all deliveries in 39 hospitals in China from 1 January 2011–31 December 2011 was evaluated for the mode of delivery and perinatal outcomes in women with oligohydramnios compared to those without known oligohydramnios after excluding preterm births, polyhydramnios, and oligohydramnios secondary to premature rupture of membranes.Results: Oligohydramnios complicated 3954 (4.4%) of the 89,050 pregnancies, analyzed. Pregnancy cases with oligohydramnios compared those without known oligohydramnios had a significantly higher incidence of preexisting or gestational diabetes mellitus, fetal growth restriction, nonreassuring fetal heart tracings, obesity and malpresentation (p<.001). The cesarean delivery (CD) rate was significantly higher in pregnancies with identified oligohydramnios compared to those without (84.4 versus 54.7%; p<.001). Furthermore, in 2/3 of these CD in pregnancies with oligohydramnios, the identification of oligohydramnios was the only indication for the CD. In pregnancies with oligohydramnios, vaginal delivery did not significantly increase the risks of adverse outcomes compared to vaginal delivery without oligohydramnios, except postpartum complication.Conclusion: CD is not indicated in term pregnancies with isolated oligohydramnios. Vaginal delivery of oligohydramnios is not associated with increased perinatal mortality.