Drug abuse, a well-documented problem found in all socioeconomic groups, knows no cultural boundaries. It does not spare pregnant women; in fact, pregnancy magnifies drug problems because both mother and child experience the consequences. Pregnant women are vulnerable physiologically and psychologically, while the fetus suffers both directly from the drug and indirectly from comorbid effects of the mother’s drug use. The long-term outcomes are just now coming to light, and effects on the infant clearly can be lifelong. Identifying those at risk is not easy, and options that are available once identification has been made are not ideal.

The “addicted newborn” is not an agreed-upon clinical term. It is used to refer to infants who exhibit some behavioral changes during the newborn period and who test positive for drugs of abuse. The term’s true meaning is that providers are able to recognize some infants who have been exposed to drugs of abuse. It does not include exposed infants who are not detected in the newborn period or whose mothers, for medical reasons, used prescription drugs, the effects of which may not be known. A useful reference about the safety and potential effects of most prescription drugs in pregnancy and breastfeeding is Drugs in Pregnancy and Lactation (Briggs, Freeman, & Yaffe, 1998).

Although not all primary care providers are involved in obstetric care, an understanding of pregnancy can help them to comprehend the effects of drug abuse on the mother and unborn child. Intoxication, a well-described risk factor for unprotected sex and therefore pregnancy, may affect the woman’s response to a resulting pregnancy for which she was unprepared. While the psychological effects on the woman cannot be underestimated, the conceptus is spared any direct physiologic effects because no transfer of toxins occurs before implantation in the uterus. Once the conceptus has implanted in the uterus, all subsequent nourishment comes from the placenta. The growing fetus then is exposed to the same things as the mother. The degree of exposure depends highly on the substance. The mother rapidly metabolizes some drugs, so the fetus is relatively spared. The placenta may easily transfer drugs with a longer half-life, with effects concentrating in the fetus. The fetus has certain capabilities, which vary according to fetal age and level of exposure, to metabolize and clear drugs. Pregnancy is a huge metabolic demand on the mother; when combined with drug use and poverty, it often results in poor maternal nutrition. Further, maternal drug use clearly is associated with sexually transmitted infections (STIs), many of which can infect and damage the fetus.

Estimates of the numbers of pregnant women who abuse drugs are unclear and vary according to the study method used. Self-reported use during prenatal care is considered accurate for those who report drug abuse. Self-reporting measures do not provide data about pregnant women who choose not to report or deny drug use or who are lost to reporting measures because they do not receive prenatal care. Other reports represent results of toxicology screening at delivery, which is an accurate indicator of drug use immediately preceding delivery but is inaccurate about drug use that may have occurred earlier in the pregnancy. Data from the most recent national survey of pregnancy and health (National Institutes of Health, 1992) suggest that 10% of pregnant women smoke cigarettes, 10% drink alcohol, and 5% use illegal drugs. Rates of illegal drug use were higher among unmarried, uneducated, and unemployed women and among women on public assistance. The problem exists, however, in all socioeconomic, ethnic, and geographic groups. The most common illegal drug used was marijuana, followed by cocaine (National Institutes of Health, 1996). At least 12% of babies born in the United States are exposed perinatally to drugs of abuse. Even if one added up the frequency of all the different diseases routinely screened for in the newborn period, from metabolic diseases to hearing loss, the total would not come close to the incidence of perinatal drug exposure.