Latency following preterm prelabor rupture of membranes before 34 weeks of gestation and its association with perinatal outcomes: a retrospective cohort study

PURPOSE: To evaluate the association between latency duration and perinatal outcomes in pregnancies complicated by preterm prelabor rupture of membranes (PPROM) before 34 weeks of gestation, and to assess the role of gestational age at PPROM and amniotic fluid volume. METHODS: This retrospective cohort study included pregnancies complicated by PPROM before 34 weeks of gestation managed expectantly at a tertiary care center. Latency duration was defined as the interval from membrane rupture to delivery. Composite neonatal and pregnancy adverse outcomes were analyzed using latency-based time-to-event methods. Cox proportional hazards models were used to assess the independent associations of gestational age at PPROM and amniotic fluid pocket with adverse pregnancy and neonatal outcomes. RESULTS: A total of 278 pregnancies were included in the final analysis. Latency duration was strongly associated with gestational age at PPROM, with progressively shorter latency observed at more advanced gestational ages. Larger residual amniotic fluid pockets were independently associated with prolonged latency. In latency-based Cox models, gestational age at PPROM was significantly associated with both pregnancy-adverse and neonatal composite outcomes. In contrast, latency duration itself and residual amniotic fluid volume were not independently associated with adverse neonatal outcomes after accounting for gestational age variables. CONCLUSIONS: In pregnancies complicated by PPROM before 34 weeks of gestation, gestational age at membrane rupture is the principal determinant of latency duration and perinatal outcomes. Latency should be interpreted as a gestational-age-dependent phenomenon rather than an independent predictor of neonatal risk, supporting individualized expectant management that prioritizes gestational age advancement while balancing maternal risk.