881: The optimal timing of induction of labor in uncomplicated twin pregnancy

Abstract

Recent guidelines recommend the planned delivery in twin pregnancy as 38 weeks for uncomplicated dichorionic twin pregnancies and as 34-37+6 weeks for uncomplicated monochorionic diamniotic twin pregnancies. However, the optimal timing of induction of labor in twin pregnancies has not been well studied. In the current study, we compared the pregnancy and neonatal outcomes between women with induction at 37 weeks and those who were nonintervention at 37 weeks and allowed the pregnancy to progress after the time. The study population consisted of 1228 term twin pregnant women who were candidates for trial of labor. They were divided into 2 groups: group 1, women who were planned as induction of labor at 37-37+6 weeks (induction group, n=488 in dichorionic twin, 143 in monochorionic twin); group 2, women who were nonintervention at 37 weeks and allowed the pregnancy to progress after the time. (expectant management group, n=384 in dichorionic twin, 92 in monochorionic twin). The timing of induction after 38 weeks in group 2 was at the discretion of the attending physician. Women who delivered due to obstetric indication (ex. preeclampsia, oligohydramnios, fetal growth restriction) and cases with fetal death in utero or fetal anomaly were excluded. The primary outcome was cesarean section rate and perinatal outcomes (Apgar scores, neonatal intensive care unit (NICU) admission, umbilical cord blood gases, neonatal morbidity). No significant differences were observed in cesarean delivery rate between two groups regardless of chorionicity. In monochorionic twin pregnancies, neonates born to women in group 2 (expectant management group) had higher risk for admission to NICU and lower pH in cord blood than neonates in group 1. In dichorionic twin pregnancies, the perinatal outcomes were not different between the two groups. Induction of labor at 37 weeks resulted in reduced adverse perinatal outcomes compared to expectant management in monochorionic twin pregnancies. The optimal timing of induction of labor in dichorionic pregnancies beyond 38 weeks needs further studies.