- To evaluate the risk factors for development of neonatal morbidity in cases of preterm premature rupture of membranes (PPROM). The study population consisted of 2326 singleton preterm births occurring between 1994 and 1997 at Soroka University Medical Center. The neonatal morbidity included respiratory distress syndrome, intraventricular hemorrhage (grade III-IV), necrotizing enterocolitis, periventricular leukomalacia, bronchopulmonary dysplasia, neonatal pneumonia and sepsis. A cross-sectional study was designed to compare neonatal morbidity between two groups: the study group consisted of patients with PPROM (n = 376) and the comparison group of patients without PPROM (n = 1950). The prevalence of the neonatal morbidity associated with PPROM was 13.0% (49/376). There was no statistically significant difference in neonatal morbidity rates between the PPROM group and the group with intact membranes in any of the birth-weight groups (Mantel-Haenszel weighted odds ratio 1.20; 95% CI 0.80-1.20), or gestational-age groups (Mantel-Haenszel weighted odds ratio 1.03; 95% CI 0.79-1.55). There was no statistically significant difference in neonatal morbidity between patients with PPROM and those with intact membranes according to clinical chorioamnionitis. Congenital anomalies did not influence the neonatal morbidity when comparing patients with and without PPROM (44.4% vs. 32.8%, respectively; p = 0.23). PPROM was not an independent risk factor for neonatal morbidity in preterm births. Neonatal morbidity was affected mainly by prematurity itself, rather than by the occurrence of PPROM.