Study results published in The Journal of Pediatrics showed that preterm boys were more likely to exhibit certain cognitive, neurologic and behavioral deficits than preterm girls.
“The higher risk among boys for certain neurological impairments, but not others, suggests that injurious exposures and/or mechanisms of injury are domain specific,” Karl C.K. Kuban, MD, chief of the division of pediatric neurology at Boston Medical Center, told Infectious Diseases in Children. “For example, we have identified inflammation as an important risk factor for cognition-related, but not autism-specific, outcomes at 2 years.”
Karl C.K. Kuban
Previous studies have suggested that overall preterm boys have greater neonatal mortality and suffer more cognitive deficits during infancy and early childhood than preterm girls, Kuban said. A 2014 meta-analysis reported, however, that the greater severity of these neurocognitive deficits begins to decline after 5 years, the researchers wrote.
As part of the multicenter Extremely Low Gestational Age Newborns (ELGAN) cohort study, Kuban and colleagues evaluated 446 boys and 428 girls aged 10 years who were initially assessed between 2002 and 2004 as extremely preterm infants. Parents reported on their child’s behavior, development and seizures, while children underwent neuropsychological battery and testing for autism spectrum disorder. The researchers defined preterm as being born before 28 weeks’ gestation.
The researchers found that 28% of boys and 21% of girls exhibited moderate to severe cognitive, neurologic and behavioral deficits. They also learned that 15% of boys and 8% of girls had microcephaly, and 6% of boys and 4% of girls required assistive devices to walk. In contrast, the investigators reported that 10% of both boys and girls had a history of seizures and that an equal percentage (7%) had epilepsy. Further, the researchers determined that 9% of boys and 5% of girls had ASD, a nearly 2:1 ratio that Kuban said unexpectedly was smaller than the 4:1 autism ratio between boys and girls in the general population.
“We intend to study further the contribution of prenatal exposures that influence particular genes, which have the capacity to modify risk for various adverse neurological, cognitive and behavioral outcomes,” Kuban said. – by Will Offit
Disclosure: The researchers report no relevant financial disclosures.