The effects of oligohydramnios on perinatal outcomes after preterm premature rupture of membranes

Abstract

Objective Amniotic fluid plays a vital protective role in fetal growth and development. Low amniotic fluid index (AFI) during pregnancy increases risk of adverse perinatal outcomes. Prior studies reported association of oligohydramnios (AFI<5 cm) with shorter latency period and inconsistent correlation with chorioamnionitis after preterm premature rupture of membranes (PPROM). We studied effects of oligohydramnios on perinatal outcomes after PPROM. Methods A retrospective cross-sectional study was performed at our medical center on women with PPROM between 23 to 34 weeks during 2014 to 2016. The primary predictor variable was AFI of <5 cm or ≥5 cm in relationship to perinatal outcomes. Results From a total of 117 PPROM cases reviewed, 46 women had AFI<5 cm and 71 had AFI≥5 cm. Length of stay (LOS) in neonatal intensive care unit (NICU) was 42 days for AFI<5 cm versus 26.5 days for AFI>5 cm (p<0.007). The mean neonatal Apgar scores at 1 and 5 minutes (5.2 and 7.4 respectively) were lower in the AFI<5 cm group compared to AFI≥5 cm (6.9 at 1 minute and 8.4 at 5 minutes, p<0.001). Conclusion Oligohydramnios after PPROM is associated with adverse perinatal outcomes such as lower Apgar scores and longer LOS in the NICU. No association was observed with latency period and chorioamnionitis.