Induction of labor in term pregnancies with isolated polyhydramnios: Is it beneficial or harmful?

Objective: To compare rates of adverse pregnancy outcomes in term pregnancies complicated by polyhydramnios between women who had induction of labor (IOB) versus women who had expectant management.

Methods: This multicenter retrospective study included term pregnancies complicated by isolated polyhydramnios. Patients who underwent IOB were compared with those who had expectant management. The primary outcome was defined as a composite adverse maternal outcome, and secondary outcomes were various maternal and neonatal adverse outcomes. Univariate analyses were followed by multivariate logistic regression.

Results: A total of 865 pregnancies with term isolated polyhydramnios were included: 169 patients underwent IOB (19.5%), while 696 had expectant management and developed spontaneous onset of labor (80.5%). Women who underwent IOB had significantly higher rates of composite adverse maternal outcome (23.1% vs 9.8%, P < 0.01), prolonged hospital stay, perineal tear grade 3/4, intrapartum cesarean, postpartum hemorrhage, blood products transfusion, and neonatal asphyxia compared with expectant management. While the perinatal fetal death rate was similar between the groups (0.6% vs 0.6%, P = 0.98), the timing of the loss was different. Four women in the expectant management group had a stillbirth, while in the induction group one case of intrapartum fetal death occurred due to uterine rupture. Multivariate analyses revealed that IOB was associated with a higher rate of composite adverse maternal outcome (adjusted odds ratio, 2.22 [95% CI, 1.28-3.83]; P < 0.01).

Conclusion: IOB in women with term isolated polyhydramnios is associated with higher rates of adverse maternal outcomes in comparison to expectant management. Further research is needed to determine the optimal approach for the management of isolated polyhydramnios at term.