COCAINE EXPOSURE DURING PREGNANCY - IMPROVING ASSESSMENT WITH RADIOIMMUNOASSAY OF MATERNAL HAIR

Objective: To compare radioimmunoassay of postpartum maternal hair sam ples with a structured maternal interview for the detection of cocaine use during pregnancy. Methods: Radioimmunoassay of hair samples obtai ned postpartum was compared with self-report of cocaine use obtained b y confidential, structured interviews of 405 post-partum women. Result s: Cocaine or benzoylecgonine was detected in the hair samples of 129 of the 148 women (87%) who reported using cocaine at least once during pregnancy. Thirty-six of 257 women (14%) who reported that they had u sed no cocaine during pregnancy had positive hair tests. Positive hair assay with negative self-report was significantly more common among w omen who were unmarried (P = .001), African-American (P < .001), and m ultiparous (P = .035). Conclusions: Hair analysis is a valuable comple ment to maternal self-report by interview. The methods used together p rovide a useful clinical and research technique yielding a comprehensi ve estimate of gestational cocaine exposure. Either method alone may r esult in misclassification of gestational cocaine exposure.