Prevalence of illicit drug use at the end of pregnancy: a cross-sectional study at the time of birth

BACKGROUND: Drug use during pregnancy is associated with adverse perinatal outcomes. This study was conducted to assess the prevalence of consumption of drugs of abuse in pregnant women at the end of gestation. METHODS: Cross-sectional study of all consecutive pregnant women in labor admitted to a regional hospital in Calella (Barcelona, Spain) in labor over one year (2014-2015). Women who gave written consent to take part in the study provided a urine sample on admission and completed a questionnaire with toxic-habit-related questions. RESULTS: The study population included 862 women, 721 (83.6%) of which agreed to participate. Of the 721 urine samples obtained, 719 (99.7%) were valid for analysis. The prevalence of drugs of abuse was 5.4% (N.=39). Cannabis was the most frequently detected substance. No participant tested positive for opioids. In the multivariate analysis, predictors of illicit drug use were history of more than two abortions, premature delivery, self-reporting of consumption during pregnancy, poor obstetric control during gestation, and consideration of vulnerable pregnant woman. Based on the 13 coefficients of these five factors, a scoring system for discriminating positivity or negativity of drugs of abuse in urine testing was calculated (area under the ROC 0.84). CONCLUSIONS: The prevalence of consumption of drugs of abuse at the end of pregnancy was 5.4%. A simple test based on five anamnestic variables is useful to discriminate women with positive and negative results of urine testing for drugs of abuse tested in this study.