Objective: To estimate the effect of preterm premature rupture of membranes (PROM) on neonatal mortality.
Methods: A cross-sectional study using a state perinatal database (California Perinatal Quality Care Collaborative) was performed. Prenatal data, including ruptured membranes, corticosteroid administration, maternal age, maternal race, maternal hypertension, mode of delivery, and prenatal care, were recorded. Mortality rates were compared for neonates born between 24 and 34 weeks of gestation without preterm PROM to those with recent (less than 18 hours before delivery) and prolonged (more than 18 hours before delivery) preterm PROM. Neonatal sepsis rates were also examined.
Results: Neonates born between 24 0/7 and 34 0/7 weeks of gestation from 127 California neonatal intensive care units between 2005 and 2007 were included (N=17,501). When analyzed by 2-week gestational age groups, there were no differences in mortality rates between those born with and without membrane rupture before delivery. The presence of prolonged preterm PROM was associated with decreased mortality at 24 to 26 weeks of gestation (18% compared with 31% for recent preterm PROM; odds ratio [OR] 1.79; confidence interval [CI] 1.25-2.56) but increased mortality at 28 to 30 weeks of gestation (4% compared with 3% for recent preterm PROM; OR 0.44; CI 0.22, 0.88) when adjusted for possible confounding factors. Sepsis rates did not differ between those with recent or prolonged preterm PROM at any gestational age.
Conclusion: The presence of membrane rupture before delivery was not associated with increased neonatal mortality in any gestational age group. The effects of a prolonged latency period were not consistent across gestational ages.