Sex differences in early vulnerability to cerebral injury and their neurodevelopmental implications

Abstract

Sex differences in early vulnerability to cerebral injury were examined in a 10-year cohort of preterm infants. The 173 infants, whose gestational age was 32 weeks or less, were diagnosed with intracranial hemorrhage (ICH), the most common cerebral insult in the premature neonate. Determination of ICH severity was based on neuroimaging evidence obtained during the neonatal period. Because the females in the sample exhibited greater dysmaturity coupled with lower birthweight, as compared with their male counterparts, analysis of covariance was applied to the data. After statistically controlling for the influence of potentially confounding perinatal variables, gender was found to provide a unique contribution to extent of ventricular dilation, an index of ICH severity. Male sex was associated not only with greater ventriculomegaly, but also with a higher grade of ICH. The latter effect was demonstrable in a large subsample of 72 males and 77 females whose birthweights were 1,750 g or below, and who did not differ significantly in gestational age. The implications of these results for theories about the neurobiological origins of sex differences in susceptibility to deviation from normal development are addressed. © 1994, Psychonomic Society, Inc.. All rights reserved.