Drug testing in biological samples vs. maternal surveys for the detection of substance use during whole pregnancy.

BACKGROUND Early diagnosis of nicotine, ethanol and drug use during pregnancy is critical in order to provide adequate care. Current screening procedures show limitations in terms of reliability and short windows of detection. OBJECTIVES To investigate the prevalence and identify biomarkers of substance use and changes in substance use during pregnancy. To compare drug testing results in different types of biological samples (maternal hair, meconium, placenta, umbilical-cord) with self-reported data. PARTICIPANTS AND SETTING Prospective cohort study using data from pregnant women and their newborns. METHODS Biological matrices were collected at birth and analyzed by liquid chromatography tandem mass spectrometry. A paper survey was provided to determine substance use habits. RESULTS 867 mother-newborn pairs were included. According to the analysis of biological samples, 29.1% cases were positive for one or more substances (13.6% nicotine, 8.4% ethanol, 8.3% cocaine, 6.4% cannabis, 5.7% opioids). The profile of the substance-using mother was a single woman, <28 years-old, with no higher education and unemployed. Segmental maternal hair analysis showed a decrease in tobacco, cannabis and cocaine use throughout pregnancy (p < 0.001). The level of concordance between results from interviews and from biological analyses was weak for opioids, cocaine, and cannabis (kappa coefficient < 0.40). Maternal hair detected the highest number of cases, followed by meconium and by placenta and/or umbilical-cord. CONCLUSIONS Maternal survey was not a reliable screening technique. Analysis of maternal hair detected the highest number of cases with the broadest detection window (whole pregnancy).