Pre-labor ruptured membranes prior to cesarean delivery elevate the risk of future childhood respiratory morbidity

Objective
Cesarean delivery (CD) appears to be independently associated with higher rates of respiratory morbidity in the offspring, as compared with vaginal delivery. This association, independent to birthweight and gestational age, may be related to lack of newborn exposure to maternal cervico-vaginal flora. We aimed to determine whether pre- labor rupture of membranes (PROM) prior to CD affects childhood respiratory morbidity, as compared with offspring born via CD without ruptured membranes.

Study Design
A population-based prospectively analyzed cohort analysis was performed including all singleton cesarean deliveries occurring between 1991-2014 at a single tertiary medical center. Fetuses with congenital malformations were excluded. Exposure was defined as presence of pre-labor rupture of membranes prior to the CD. Hospitalizations of the offspring up to the age of 18 years involving respiratory morbidity were evaluated. A Kaplan Meier survival curve was used to compare cumulative morbidity incidence. A Cox hazards regression model was used to control for confounders.

Results
During the study period 32,754 cesarean deliveries met the inclusion criteria. In 9.8% of cases (n=3202) PROM was documented. Rate of hospitalizations involving respiratory morbidity of the offspring up to the age of 18 years, was significantly higher in children exposed to PROM as compared with the unexposed group (6.7 % vs. 5.6%, respectively, p=0.007, Table). The survival curve demonstrated significantly higher cumulative respiratory morbidity incidence in the PROM exposed group (log rank p=0.005, Figure). In the Cox regression model, controlled for gestational age, maternal age, maternal hypertension and diabetes, ethnicity, and maternal smoking, pre- cesarean PROM exhibited an independent association with long-term childhood respiratory morbidity in the offspring (adjusted hazard ratio 1.18, 95%CI 1.02-1.36, p=0.024).

Conclusion
Fetal exposure to PROM prior to cesarean delivery appears to elevate the risk for long term respiratory morbidity in the offspring. Whether this association is related to the PROM etiology or exposure to maternal birth canal flora, is yet to be determined.