Longitudinal cognitive development of children born to mothers with opioid and polysubstance use.

BACKGROUND: Previous studies indicate an increased risk for neuropsychological difficulties in young children prenatally exposed to opioids and polysubstances, but longitudinal information is scarce. The present longitudinal study investigated whether these waned, persisted, or increased over time.

METHODS: The cognitive functioning of 72 children with prenatal opioid and polysubstance exposure and 58 children without any established prenatal risk was assessed at 1, 2, 3, 4½, and 8½ y.

RESULTS: The exposed boys had significantly and stably lower levels of cognitive functioning than the control group, whereas there were increasing differences over time for the girls. The exposed group had significantly lower IQ scores than the control group on Wechsler Intelligence Scale for Children--Revised at 8½ y after controlling for earlier cognitive abilities, and for children who were permanently placed in adoptive/foster homes before 1 y of age and whose mothers used heroin as their main drug during pregnancy (B = 17.04, 95% CI 8.69-25.38, P < 0.001).

CONCLUSION: While effects of prenatal substance exposure cannot be isolated, group effects on cognition rather increased than waned over time, even in adoptive/foster children with minimal postnatal risk.