Not all days are equal after preterm prelabor rupture of membranes: a time-dependent analysis of adverse perinatal outcomes

Objective Preterm prelabor rupture of membranes (PPROM) is associated with significant perinatal morbidity and mortality. Clinical management is typically based on inpatient monitoring, although the optimal duration and the potential role of outpatient care remain unclear. Methods In this retrospective cohort study, all women with PPROM between 15 + 0 and < 37 + 0 weeks’ gestation managed as inpatients at a tertiary center (07/2019-04/2024) were included. The primary outcome was a composite severe adverse perinatal outcome (SAPO), comprising fetal or neonatal death, neonatal sepsis, intrauterine inflammation or infection, and major obstetric complications. Time-dependent risk was analyzed using latency stratification and landmark analyses. Independent predictors were identified via multivariable logistic regression. Longitudinal clinical and laboratory changes in the five days before delivery were assessed, and predictive performance was evaluated using area under the receiver operating characteristic curve (AUC). Results A total of 300 women were included, of whom 46 (15.3%) experienced SAPO. Lower gestational age at PPROM, non-cephalic presentation, and estimated fetal weight below the 10th percentile were independently associated with SAPO, while inflammatory markers at admission showed no statistically significant independent association. The highest adjusted odds of SAPO were observed in the 6–7-day latency group (adjusted OR 6.10, 95% CI 1.45–25.62), although this subgroup comprised only 11 pregnancies. No statistically significant increase was detected in the group with latency exceeding seven days. Longitudinal increases in C-reactive protein (CRP) and leukocyte levels preceded delivery in complicated cases, but predictive performance remained limited (AUC 0.59–0.61). Conclusion These findings highlight the importance of gestational age, fetal condition, and dynamic selection during expectant management of PPROM. Prospective studies are needed to evaluate individualized monitoring strategies and the potential role of outpatient management in carefully selected patients.