AIM: To ascertain whether premature rupture of membranes (PROM) independently affects the risk of neonatal respiratory morbidity at 32-41 weeks' gestation because previous reports have given insufficient consideration to the mode of delivery and labor onset. METHODS: Data on 4,629 consecutive singleton infants were retrospectively collected. Respiratory morbidity was limited to respiratory distress syndrome and transient tachypnea of the newborn, both of which are related to prematurity. Delivery modes were divided into four groups based on the existence of PROM and of labor onset, and the respiratory morbidity was examined according to the number of weeks of gestational age. Multivariate analysis including PROM and delivery mode was conducted to examine the association of respiratory morbidity. RESULTS: Respiratory morbidity or a positive pressure requirement delivered after PROM and intact amniochorionic membranes accompanied by labor were similar at all weeks. Around 37 weeks, the absence of labor onset was associated with a risk of respiratory morbidity or positive pressure requirement. Significant respiratory risk was not associated with the incidence of PROM (adjusted odds ratio [aOR], 0.98; 95% confidence interval [CI], 0.52-1.83), interval from rupture to delivery (aOR, 1.00; 95% CI, 0.99-1.01), clinical chorioamnionitis, induction management, pregnancy-related complications, or neonatal sex. Delivery by Cesarean section and early gestational age presented a significant risk for respiratory morbidity. CONCLUSIONS: Neither PROM nor latency after PROM at 32-41 weeks affected neonatal respiratory morbidity. Avoiding Cesarean section instead of simply increasing the time to delivery may help to reduce respiratory morbidity.
AIM: To ascertain whether premature rupture of membranes (PROM) independently affects the risk of neonatal respiratory morbidity at 32-41 weeks' gestation because previous reports have given insufficient consideration to the mode of delivery and labor onset. METHODS: Data on 4,629 consecutive singleton infants were retrospectively collected. Respiratory morbidity was limited to respiratory distress syndrome and transient tachypnea of the newborn, both of which are related to prematurity. Delivery modes were divided into four groups based on the existence of PROM and of labor onset, and the respiratory morbidity was examined according to the number of weeks of gestational age. Multivariate analysis including PROM and delivery mode was conducted to examine the association of respiratory morbidity. RESULTS: Respiratory morbidity or a positive pressure requirement delivered after PROM and intact amniochorionic membranes accompanied by labor were similar at all weeks. Around 37 weeks, the absence of labor onset was associated with a risk of respiratory morbidity or positive pressure requirement. Significant respiratory risk was not associated with the incidence of PROM (adjusted odds ratio [aOR], 0.98; 95% confidence interval [CI], 0.52-1.83), interval from rupture to delivery (aOR, 1.00; 95% CI, 0.99-1.01), clinical chorioamnionitis, induction management, pregnancy-related complications, or neonatal sex. Delivery by Cesarean section and early gestational age presented a significant risk for respiratory morbidity. CONCLUSIONS: Neither PROM nor latency after PROM at 32-41 weeks affected neonatal respiratory morbidity. Avoiding Cesarean section instead of simply increasing the time to delivery may help to reduce respiratory morbidity.