Confirmation of cocaine use during pregnancy: A critical review

Cocaine exposure during pregnancy is a major public health issue. Diagnosing maternal and fetal exposure to cocaine is important not only because of the deleterious effects of this active xenobiotic on the fetus, but also because most women who use cocaine long after pregnancy has been diagnosed are addicted to the drug and will continue to use it after the birth of the child. Under these circumstances, a positive neonatal hair test, for example, constitutes a marker of postnatal addiction, which may have grave prognostic meaning to the baby. Because maternal self-reports have a very low positive yield because of shame, guilt, and fear, the ability of the laboratory to support clinical suspicions is critical. Meconium can detect long-term fetal exposure to cocaine, but unlike hair it is available for only 1-2 days after birth. In addition, no dose-response curve has been established with clinical effects. Positive neonatal urine and blood tests for cocaine are much less common because of cocaine's short elimination half-life. Positive urine or blood tests typically reflect high-dose users.