- To characterize neonatal morbidity and mortality rates in extreme preterm deliveries (between 23 and 27 weeks' gestation) with and without PPROM, and to evaluate the association between PPROM and chorioamnionitis. A retrospective population-based study was conducted on preterm singleton pregnancies delivered between 23 and 27 weeks' gestation from 1988 to 2007. Immediate neonatal morbidity and mortality rates in pregnancies complicated by PPROM were compared to pregnancies with intact membranes. A multivariate analysis was conducted in order to determine the independent association between PPROM and chorioamnionitis. Out of 1,437 preterm deliveries, 236 (16.4%) were complicated with PPROM. There were more neonates with low 1 min (61.0 vs. 42.5%; P = 0.001) and low 5 min (30.1 vs. 23.8%; P = 0.042) Apgar scores (of less than 7) in pregnancies complicated by PPROM than in the comparison group. There were more cases of chorioamnionitis in the PPROM group born at 23-24 weeks' gestation (33.8 vs. 17.0%; P < 0.001), and in the PPROM group born at 25-27 weeks (42.0 vs. 15.5%; P < 0.001). In the group born at 23-24 weeks' gestation, there were more postpartum deaths (PPD) in the PPROM group (70.0 vs. 54.8%; P = 0.013); however, there was no significant difference in PPD in the groups born at 25-27 weeks. In the group born at 23-24 weeks, as well as at 25-27 weeks, there were fewer antepartum deaths (APD) in the PPROM group as compared to the control group (16.3 vs. 32.6%; P = 0.002, and 5.3 vs. 36.3%; P < 0.001; respectively). After adjusting for gestational age and gender, using a multivariate analysis, the association between PPROM and chorioamnionitis remained significant (OR = 3.32; 95% CI 2.43-4.51, P < 0.001). PPROM is associated with adverse perinatal outcome in deliveries between 23 and 27 weeks' gestation. Moreover, PPROM is an independent risk factor for chorioamnionitis.