Drugs of Abuse during Pregnancy: Effects upon Offspring Structure and Function

Abstract

Two percent of live-born infants suffer major birth defects. A far larger percentage develops minor defects and behavioral (functional) deficits that go unrecognized at the time of birth. Neel has estimated that genetic factors were responsible for 20 percent of all malformations, chromosomal aberrations for another 10 percent, leaving 70 percent of all birth defects attributable to viral agents, drugs, and other environmental stresses.1 It is with this last and large proportion that we will be concerned, inasmuch as they are determined by the abuse of drugs during pregnancy. A drug is any substance other than food or water that alters the functions of the body when it is absorbed. Any drug can be abused if enough of it is ingested. My discussion will be limited to widely used nonprescription drugs of abuse, and specifically, to nicotine, a central nervous system activator; a group of opiates, heroin, morphine, and methadone; and a central nervous system depressant, alcohol. The extent of drug use during pregnancy has been estimated in two recent studies. A Scottish study found that 82 percent of an unselected sample of pregnant women were on some type of prescribed medication, and that 65 percent of them self-medicated.2 When queried, 57 percent admitted to being smokers and 45 percent to using alcohol regularly. A