Substance use measures among women in early pregnancy

OBJECTIVE: Our purpose was to compare self-reported and biochemical measures for tobacco, marijuana, and cocaine exposures among women early in pregnancy. STUDY DESIGN: Women who were in the early stages of pregnancy and were examined in an inner-city emergency department were enrolled. Tobacco, marijuana, and cocaine use was measured by self-report and urinalysis. Cocaine use was also assessed by hair analysis. RESULTS: Data were available for 789 women. Among those reporting past use of tobacco, marijuana, and cocaine, 25.2%, 23.9%, and 22.7%, respectively, had positive results of urinary assays; among those reporting current use, 77.2%, 86.6%, and 75.9% had positive findings, whereas among those reporting never use 5.6%, 5.7%, and 3.6% of results were positive. Hair analysis, in comparison with urine testing, for cocaine identified 4 times as many exposures among women who reported never using cocaine. CONCLUSIONS: Urinary assays were equally likely to be positive among women reporting never use and those reporting past use of tobacco, marijuana, or cocaine. Thus women with a positive biologic assay result were as likely to deny use of tobacco as they were to deny marijuana, or cocaine.