Objective: To evaluate whether chorioamnionitis is associated with decreased Bayley II scores at age 2 years.
Methods: We conducted an observational cohort study of women and their offspring enrolled in the Eunice Kennedy Shriver National Institute of Child Health and Development's Maternal-Fetal Medicine Units Network multicenter, randomized controlled trial of magnesium for cerebral palsy prevention in pregnancies at high risk for early preterm delivery. We included nonanomalous singleton gestations and excluded pregnancies missing outcome or exposure data. Our primary exposure was chorioamnionitis, defined by the clinical diagnosis of chorioamnionitis and a maternal fever greater than 100°F. Our primary outcome was a Bayley II Mental Developmental Index score less than 70 or Psychomotor Developmental Index score less than 70 assessed at age 2 years. We also assessed Mental Developmental Index or Psychomotor Developmental Index score less than 85. We conducted bivariate analyses and fit a log-linear regression model, adjusting for related to Mental Developmental Index or Psychomotor Developmental Index score less than 70 or less than 85 with a detectable effect size estimated at a relative risk of 1.5 or greater.
Results: Of 1,574 patients in our analysis, 194 (12%) had chorioamnionitis and 1,366 (87%) had preterm premature rupture of membranes. The mean gestational age at delivery was 29 3/7 weeks. There were no significant differences in Mental Developmental Index score less than 70 (37 [19.1%] compared with 233 [17%], P=.45) or Psychomotor Developmental Index score less than 70 (29 [15%] compared with 195 [14%] P=.76) for children born to mothers with or without chorioamnionitis, respectively. After adjusting for confounders, there remained no difference in the proportion of abnormal scores in either group. However, neonates diagnosed with sepsis were found to have significantly decreased Mental Developmental Index scores.
Conclusion: Exposure to chorioamnionitis was not associated with neurocognitive defects as measured by abnormal Bayley II scores.