Labor and delivery characteristics and risks of cranial ultrasonographic abnormalities among very-low-birth-weight infants. The Developmental Epidemiology Network Investigators.

Objective: The objective of this study was to evaluate the relationships between 3 labor and delivery characteristics (duration of labor, interval between membrane rupture and delivery, and route of delivery) and 4 neonatal cranial ultrasonographic abnormalities (intraventricular hemorrhage, ventriculomegaly, echodensity of cerebral white matter, and periventricular leukomalacia).

Study Design: We prospectively gathered data on 1588 very low birth weight infants including neonatal cranial ultrasonographic studies, maternal interview, and maternal and infant chart reviews. We performed univariate and multivariate analyses.

Results: In univariate analysis vaginal delivery was associated with an increased risk of all 4 cranial ultrasonographic abnormalities. In multivariate analysis, however, vaginal delivery was no longer associated with periventricular leukomalacia. Moreover, the risks of intraventricular hemorrhage, ventriculomegaly, and echodensity attributable to vaginal delivery were no longer elevated when the sample was limited to infants born within 1 hour after membrane rupture and adjustment was made for fetal vasculitis and for other potential confounders.

Conclusion: Vaginal delivery was the only obstetric characteristic consistently associated with intracranial hemorrhage and white matter disease in these preterm infants. Because its relationship to brain lesions was markedly reduced when placental inflammation was accounted for, however, vaginal delivery may simply have acted as a marker for antecedent inflammation or infection and not as a direct contributor to brain disorders.