"Our study found significant cognitive deficits with cocaine-exposed children twice as likely to have significant delay throughout the first 2 years of life. The 13.7% rate of mental retardation is 4.89 times higher than that expected in the population at large, and the percentage of children with mild or greater delays requiring intenvetion was 38%, almost double the rate of the high-risk noncocaine- but polydrug-exposed comparison group. Because 2-year Mental Development Index scores are predictive of later cognitive outcomes, it is possible that these children will continue to have learning difficulties at school age.37,38

"Cognitive delays could not be attributed to exposure to other drugs or to a large number of potentially confounding variables. Further, poorer cognitive outcomes were related to higher amounts of cocaine metabolites in infant meconium as well as to maternal self-reported measures of amount and frequency of cocaine use during pregnancy, providing further support for a teratologic model. Developing neural systems of the fetal brain may be directly affected by cocaine’s adverse effects on monoaminergic system development or indirectly affected through vascular constriction with subsequent decreases in placental blood flow and generalized hypoxemia."

Source

Singer, L. T., Arendt, R., Minnes, S., Farkas, K., Salvator, A., Kirchner, H. L., & Kliegman, R. (2002). Cognitive and motor outcomes of cocaine-exposed infants. JAMA, 287(15), 1952–1960. doi.org/10.1001/jama.287.15.1952