Perinatal substance abuse and the drug-exposed neonate.

Tobacco and alcohol are the substances most abused during pregnancy. Alcohol (ethanol) is the human teratogen that produces the most serious neurobehavioral effects on the fetus. Cocaine is associated with spontaneous abortions, premature labor, precipitous labor, stillbirths, meconium staining and abruptio placentae. Heroin use during pregnancy has been associated with low birth weight, miscarriage, prematurity, microcephaly and intrauterine growth retardation. Marijuana is not scientifically linked to significant teratogenic effects. Since most substance abusers use multiple drugs, a positive screen for marijuana may indicate a high-risk patient. Cigarette smoking has been associated with spontaneous abortions, premature rupture of membranes, preterm delivery, perinatal death, low birth weight infants, and deficits in learning and behavior.