Clinical chorioamnionitis and the prognosis for very low birth weight infants

To determine the effects of clinical chorioamnionitis on neonatal morbidity and mortality in very low birth weight infants.

This was an observational cohort analysis of all singleton live-born infants weighing 500-1500 g at 24 weeks' or greater gestational age and born between 1988 and 1996 at Parkland Memorial Hospital, Dallas, Texas. Chorioamnionitis was diagnosed on the basis of maternal fever of 38C with supporting clinical evidence, which included fetal tachycardia, uterine tenderness, and/or malodorous infant, and the absence of another source of infection. Multiple logistic regression analysis was used to adjust for outcomes of interest.

Ninety-five of 1367 very low birth weight infants (7%) were exposed to chorioamnionitis. Neonatal sepsis, respiratory distress syndrome, seizure in the first 24 hours of life, intraventricular hemorrhage (grade 3 or 4), and periventricular leukomalacia were all significantly increased with chorioamnionitis, after adjusting for preterm ruptured membranes, pregnancy-associated hypertension, cesarean birth, gestational age, and birth weight. The odds ratios for intraventricular hemorrhage, periventricular leukomalacia, and seizures in the first 24 hours were 2.8 (95% confidence interval [CI] 1.6, 4.8), 3.4 (95% CI 1.6, 7.3), and 2.9 (95% CI 1.2, 6.8), respectively.

Our results suggest a link between clinical chorioamnionitis and several indices of neonatal morbidity in the very low birth weight infant. Chorioamnionitis appears to make the very low birth weight infant particularly vulnerable to neurologic damage.