Still, most fare far better in the first few years after birth than many experts once predicted, contradicting the notion that as a rule, cocaine-exposed infants would be born with devastating birth defects or miss major developmental milestones.
"I think the early information we had was that these children might be irreversibly damaged - that they would potentially have lots of problems in school, that they might have lots of behavior problems, that they might have problems thinking and learning," said UF neonatologist Marylou Behnke, M.D.
Instead, UF researchers write in the April online issue of the Journal of Pediatric Psychology, prenatal cocaine exposure is linked to smaller head circumference at birth and to less optimal home environments, which in turn have direct yet mild effects on developmental outcome at 3 years of age. Those effects persist at ages 5 and 7, once more demands are placed on the children during the formal school years, according to related findings the researchers presented at the recent annual meeting of the Society for Research in Child Development.
"We have found that at age 3, the more cocaine the child was exposed to, the smaller the head circumference at birth, and the smaller the head circumference at birth, the worse the developmental or cognitive outcomes," said Behnke, adding that head circumference at birth is an important measure because generally the head grows as brain size increases. "So cocaine is not directly affecting outcome, but it affects this intermediary measure that we're looking at that then goes on to affect outcome. We think that head circumference may be some sort of a marker for what is going on in the prenatal environment, that it's a proxy marker for other things."
Contact: Melanie Ross
University of Florida