Preterm premature rupture of the membranes is associated with a reduction in neonatal respiratory distress syndrome

OBJECTIVE: The purpose of this study was to evaluate the effect of preterm premature rupture of the membranes on the frequency of respiratory distress syndrome among singleton pregnancies that are complicated with preterm delivery. STUDY DESIGN: We performed a retrospective analysis of singleton pregnancies that were delivered between 24 and 34 weeks of gestation. Patients were categorized on the basis of membrane integrity into two groups: ruptured versus intact. All patients received prophylactic antibiotics and a single course of antenatal betamethasone. Data were analyzed with the Student t test, the chi(2) test, and the Fisher exact test. Multiple logistic regression analysis was performed to examine the effect of possible confounding variables that were considered risk factors for respiratory distress syndrome. Probability values of <.05 for all two-tailed tests were considered significant. RESULTS: A total of 366 patients were included (99 patients in the preterm premature rupture of the membranes group and 267 patients in the intact membranes group). Patients were delivered at 30.7 +/- 2.9 and 30.1 +/- 2.7 (mean +/- SD) weeks of gestation, with birth weights of 1620 +/- 594 and 1417 +/- 501 g, respectively. The frequency of respiratory distress syndrome in the neonate was significantly lower in the preterm premature rupture of the membranes group than in their intact counterparts (17% vs 39%, P < .001). Multiple logistic regression analysis confirmed that preterm premature rupture of the membranes (odds ratio, 0.16; 95% Cl, 0.08-0.34) was independently associated with a reduction in the frequency of respiratory distress syndrome. CONCLUSION: In the clinical setting of delivery before 34 weeks of gestation, preterm premature rupture of the membranes is associated with a significant decrease in the frequency of neonatal respiratory distress syndrome.