Hemodynamic and antecedent risk factors of early and late periventricular/intraventricular hemorrhage in premature infants.

To determine hemodynamic and antecedent risk factors for early and late periventricular/intraventricular hemorrhage (P/IVH) in premature infants. Two prospective cohort studies of 126 (1995-1996) and 128 (1998-1999) infants born <30 weeks' gestation. Head ultrasounds were performed at <6 hours of age, and at 7 and 28 days of age. P/IVH was classified as early (present on initial scan) and late (developed subsequently). Echocardiographic measurement of the superior vena cava (SVC) flow was performed at <6, 10, and 24 hours of age. Infants with early P/IVH were significantly more likely to be born by vaginal delivery in both cohorts (1995-1996 adjusted odds ratios [OR]: 13.29; 1998-1999 adjusted OR: 18.15). An association with a 1-minute Apgar < or =4 was only significant in the 1998-1999 cohort (adjusted OR: 9.14). Low SVC flow was the only independent risk factor for late P/IVH in both cohorts (1995-1996 adjusted OR: 20.39; 1998-1999 adjusted OR: 5.16). Adjusted for perinatal risk factors, low SVC flow was associated with lower gestation and higher average mean airway pressure in both cohorts, and with a large diameter ductus diameter only in the 1995-1996 cohort. Early and late P/IVH have distinct and different risk factors. Early P/IVH is associated with vaginal delivery and possibly low Apgar scores. Late P/IVH is associated with antecedent low SVC flow in the first day.