Background: Chorioamnionitis (CAM) may accelerate lung maturation in fetuses. It is possible that CAM prevents infant death after live birth.
Methods: A retrospective study of live-born singletons at < 32 weeks of gestation between 1993 and 1997. Perinatal risk factors for adverse outcomes were analyzed using a logistic regression model, with special reference to the presence of histologically confirmed CAM. Adverse outcomes included infant death before 1 year of age, and survival with cerebral palsy and/or mental retardation.
Results: A total of 81 infants, weighing 1181 +/- 426 g, were born at 28.1 +/- 2.3 weeks of gestation. Of those, 15 (19%) died before 1 year of age, while 16 (20%) infants developed major handicaps by 1.5 years of age (six with cerebral palsy, eight with mental retardation, and two with both cerebral palsy and mental retardation). CAM, present in 44 women, was significantly associated with a reduced risk of death after live birth, with an odds ratio of 0.11 (p = 0.01). Only the presence of such intracranial lesions as periventricular leukomalacia and intraventricular hemorrhage were significantly associated with an increased risk of major handicaps (odds ratio of 11.0, p = 0.04). Adverse outcomes occurred in a similar proportion of infants in groups without CAM (14/37) and with CAM (17/44). However, among infants with adverse outcomes, the number of deaths was significantly higher in the group without CAM (10/14) vs. with CAM (5/12) (p < 0.05).
Conclusions: The presence of CAM may somehow prevent infant death after live birth. Larger studies are required to confirm this phenomenon.