A neonate was noted to have mild growth retardation and facial dysmorphology. The mother was a known abuser of several substances. This infant's problem most likely resulted from maternal intake of which of the following?

Fetal alcohol syndrome is the most common acquired cause of mental retardation in the United States. The common features of the syndrome include intrauterine growth retardation, facial dysmorphology, neurologic impairment, and other congenital anomalies. In cases with lesser manifestations, termed fetal alcohol effect, children later suffer from mental retardation and minor dysmorphic features. Cocaine (choice B) may cause neonatal difficulties and heroin (choice D) intake may result in neonates that are addicted to that opiate, but they are not associated with characteristic facial dysmorphology.Diagnosis: Fetal alcohol syndrome