Impact of prolonged preterm premature rupture of membranes and oligohydramnios on neonatal outcomes in extremely preterm infants: A nationwide cohort study.

BACKGROUND: Prolonged preterm premature rupture of membranes (PPROM) may support fetal maturation but it also increases the risk of complications such as oligohydramnios. The aim of this study was to assess the effect of PPROM latency and oligohydramnios on neonatal outcomes in extremely preterm infants. METHODS: This study analyzed 940 infants born at < 28 weeks of gestation after PPROM using data from the Korean Neonatal Network. The infants were divided into two groups based on latency period: short (1-20 days, SP) and long latency (≥ 21 days, LP). Each group was further stratified by the presence of oligohydramnios, yielding four subgroups for analysis. RESULTS: Compared with the SP group, infants in the LP group had higher rates of oligohydramnios and neonatal complications, such as air-leak syndrome, early pulmonary hypertension, and necrotizing enterocolitis. Mortality was significantly higher in the LP group (32.3%) than in the SP group (20.1%) (P < 0.001). Subgroup analysis revealed that only the LP with oligohydramnios group had significantly higher mortality than all the other subgroups, regardless of gestational age at birth. CONCLUSION: Prolonged latency (≥ 21 days) combined with oligohydramnios significantly increases mortality risk in extremely preterm infants, highlighting the need for individualized management strategies that consider both latency period and oligohydramnios.