Developing language skills of cocaine-exposed infants

To assess whether there is an association of level of fetal cocaine exposure to developmental precursors of speech-language skills at 1 year of age, after controlling for confounding factors.

In a prospective, longitudinal, quasi-experimental, matched cohort design, 3 cocaine exposure groups were defined by maternal self-report and infant meconium assay: nonexposure (n = 131), heavier exposure (n = 66), >the 75th percentile for maternal self-report and >the 70th percentile of benzoylecgonine concentration, and all others as lighter exposure (n = 68). At 1 year of age, the Preschool Language Scale-3 was administered by examiners unaware of infant drug status.

Independent of confounding drug, medical, and environmental factors, more heavily exposed infants had lower auditory comprehension scores than nonexposed infants and lower total language scores than lighter and nonexposed infants. More heavily exposed infants were also more likely to be classified as mildly delayed by total language score than nonexposed infants. There were positive linear relationships between the concentration of benzoylecgonine in meconium and all outcomes and between maternal report of severity of prenatal cocaine use with poorer auditory comprehension indicating a relationship between amount of exposure and poorer outcomes.

This study documents significant behavioral teratogenic effects of fetal cocaine exposure on attentional abilities underlying auditory comprehension skills considered to be precursors of receptive language. Pediatricians are in a unique position to monitor early development of cocaine-exposed infants and make timely referrals for intervention.