title: Male gender is associated with intraventricular hemorrhage.
abstract: OBJECTIVE
  The goal was to examine the association of gender with intraventricular hemorrhage (IVH) or periventricular leukomalacia (PVL) in a large national database.
  
  
  METHODS
  The National Inpatient Sample database was analyzed for the years 1998, 1999, 2001, 2002, and 2004 and its pediatrics version for the years 1997, 2000, and 2003. The National Inpatient Sample and its pediatrics version are annually collected databases for inpatient admissions from >1000 hospitals across the United States. We included all very low birth weight (VLBW) infants (birth weight [BW] of <1500 g) and excluded infants with major congenital anomalies. VLBW infants with IVH or PVL were identified by using International Classification of Diseases, Ninth Revision, diagnostic codes. We analyzed the data by using chi(2) and Fisher's exact tests to calculate odds ratios (ORs) and logistic regression analysis to control for possible confounders.
  
  
  RESULTS
  The data included 104 847 VLBW infants. With controlling for significant confounders, IVH was associated with male gender (15.9% vs 13.6%; adjusted OR [AOR]: 1.15 [95% confidence interval: 1.11-1.19]; P < .001). More boys than girls had severe IVH (38% vs 32.7%; AOR: 1.18 [95% confidence interval: 1.06-1.32]; P < .004). The increased rates of IVH and severe IVH in boys were significant in the BW subgroups of <1000 g and 1000 to 1499 g. The association of male gender with IVH and severe IVH was more significant in infants of 1000 to 1499 g (AOR: 1.19 vs 1.14; P = .006). The incidence of PVL in VLBW infants was 0.41%, and rates did not differ between genders (0.38% vs 0.43%; P = .42).
  
  
  CONCLUSIONS
  Compared with girls, VLBW male newborns are at greater risk to develop IVH and severe IVH but not PVL. The association of male gender with IVH or severe IVH is stronger with higher BWs.
authors.affiliation: George Washington University Medical Center, Newborn Services, 900 23rd St NW, Suite G-2092, Washington, DC 20037, USA. mmohamed@mfa.gwu.edu
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Mohamed
authors.forename: Hany
authors.initials: H
authors.lastname: Aly
mesh_terms: D002543:Cerebral Hemorrhage / Q000453:epidemiology*; D016208:Databases, Factual; D005260:Female; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D007969:Leukomalacia, Periventricular / Q000453:epidemiology*; D008297:Male; D012737:Sex Factors; D014481:United States / Q000453:epidemiology