Intraventricular hemorrhage risk factors in very low birth weight newborns: a case-control study

Objective: Identification of variables that affect the risk of severe intraventricular hemorrhage (IVH) in very low birth weight (VLBW) newborns. Methods: Analytic case-control study, in a population consisting of all VLBW newborns admitted to the Neonatal Intensive Care Unit of a maternity hospital, between January 2002 and December 2007. The authors considered as cases all VLBW newborns with severe IVH (grade >= 3), and control all VLBW newborns without IVH. Independent variables included obstetric, perinatal and neonatal diagnosis and therapy. Bivariate analysis and multivariate logistic regression analysis were performed. Results: During this period, of the 864 VLBW newborns admitted to the Neonatal Intensive Care Unit, 9.7% had severe IVH. With bivariate analysis an association between severe IVH, gestational age and birth weight was found. Prenatal care and pre-eclampsia were associated with a decrease in the incidence of severe IVH. Amnionitis, being outborn, vaginal delivery, male gender, intubation in the delivery room, surfactant, hyaline membrane disease, pneumothorax, necrotizing enterocolitis (NEC) perforation and oscillatory high frequency ventilation were associated with an increased incidence of severe IVH. By multivariate logistic regression, the variables associated with increased risk of severe IVH were: pneumothorax (OR = 3.8; 95% CI = 1.7-8.3), NEC with perforation (OR = 8.8; 95% CI = 1.7-45.0), vaginal delivery (OR = 2.0; 95% CI = 1.0-4.1) and high frequency ventilation (OR = 4.8; 95% CI = 1.3-17.3). The following were protective of severe IVH: gestational age (OR = 0.61; 95% CI = 0.52-0.72), patent ductus arteriosus treatment with indomethacin (OR = 0.26; 95% CI = 0.11-0.6) and fertility treatment (OR = 0.24; 95% CI = 0.06-0.94). Conclusion: These data outline the importance of improvement of pre and neonatal care to reduce severe IVH.