Predictors of drug use during pregnancy: The relative effects of socioeconomic, demographic, and mental health risk factors

Abstract

BACKGROUND: With limited Canadian research on predictors of drug use during pregnancy, the primary objective was to assess the relative effects of socioeconomic, demographic, and mental health risk factors associated with drug use during pregnancy. Predictors of an Apgar score < 7 and fetal macrosomia were examined as secondary outcomes. METHODS: This retrospective cohort study consisted of 25,734 pregnant women from Southwestern Ontario. Data were prospectively obtained from perinatal and neonatal databases at a tertiary hospital in London, Ontario. Using a Geographic Information System, neighborhood-level socioeconomic variables were obtained by mapping maternal postal codes. Separate logistic regressions were computed for all outcome variables. RESULTS: The rates of alcohol, tobacco, and cannabis use during pregnancy were 1.9%, 16.2%, and 2.3%, respectively. The mean maternal age was 29.4±5.4 years. Maternal age was inversely associated with alcohol, tobacco and cannabis use, whereas lone-parent household, depression, and anxiety increased the odds of substance use. Depression was the top risk factor of all three substances. Compared to women who were not depressed during pregnancy, women who were depressed were 2.15 times more likely to use alcohol (95% CI: 1.60, 2.90), 1.70 times more likely to smoke tobacco (95% CI: 1.48, 1.95), and 2.56 times more likely to use cannabis (95% CI: 1.95, 3.35). Adverse birth outcomes were also associated with overweight and obesity, gestational diabetes and insulin-dependent diabetes. CONCLUSIONS: Maternal depression is the primary risk factor of drug use during pregnancy. Policy interventions that target at-risk women are important considerations to improve maternal mental health.