Hypernatremia and grade III/IV intraventricular hemorrhage among extremely low birth weight infants

Objective: To identify the risk factors contributing to intraventricular hemorrhage (IVH) in extremely low birth weight infants during early postnatal life, after appropriate matching for gestational age (GA) and birth body weight (BBW). Study Design: A case-control retrospective study was designed to evaluate preterm infants with a GA <= 26 weeks and a BBW <= 1000 g admitted to our hospital during a 7.5-year period. From a cohort of 347 preterm infants, 36 infants (10.7%) had severe IVH (grades III and/or IV). We selected a control group of 36 preterm infants without IVH who were closely matched for GA (+/- 1 week) and body weight (+/- 100 g). Univariate and multivariate logistic regression analyses were performed to identify risk factors for severe IVH. Result: The GA and BBW of the IVH and control groups were 24.6 +/- 1weeks and 764.4 +/- 118.5 g, and 24.8 +/- 0.9 weeks and 771.5 +/- 125.9 g, respectively. Vaginal delivery, male sex, resuscitation in the delivery room, high sodium serum levels (meq l(-1)) (162.6 vs 148.8), fluctuation of serum sodium (meq l(-1)) (17.3 vs 6.2), pH, PaCO2, hemoglobin and platelet counts were associated with an increased risk of severe IVH. Multivariate logistic regression indicated that sodium fluctuations >13 meq l(-1), vaginal delivery, male sex and hemoglobin fluctuations are strongly associated with the development of severe IVH. Conclusion: Hypernatremia and fluctuations of sodium seem to be related to early severe IVH among preterm infants; however, further studies are required to clarify the causal relationship. Journal of Perinatology (2011) 31, 193-198; doi:10.1038/jp.2010.86; published online 29 July 2010