Utilizing Biomarkers to Assess Prevalence and Trends of Substance Use During Pregnancy in Canada

Substance use during pregnancy is associated with numerous risks to both mother and fetus. Studies of the prevalence and trends of substance use during pregnancy have predominantly relied on maternal self-report, which is known to be unreliable and inaccurate. The emerging use of biomarkers has presented researchers and clinicians with the opportunity to assess this complex matter in a more objective and reliable manner. The overall objective of the research described in this thesis is to utilize biomarkers to assess prevalence rates and trends of substance use during pregnancy in Canada. This objective was addressed through three studies focusing on distinct populations. The first study focuses on a highly specific population of methadone-using pregnant women involved in social services, and found that rates of polydrug use (specifically opioid use) were similar to a negative control group, with approximately half of individuals continuing to use additional opioids during pregnancy. The second study highlights a routine urine drug screen program within the obstetric unit of a regional hospital; we conclude that the prevalence of substance use in this population is close to three times the national average, and that drug use during pregnancy is associated with more maternal and neonatal complications. Lastly, the third study aims to estimate the prevalence of heavy fetal alcohol exposure through the analysis of fatty acid ethyl esters in meconium samples collected nationwide, and reveals that the prevalence ranges between 1.16 and 2.40%, the equivalent of at least 1,800 new cases of Fetal Alcohol Spectrum Disorder in Canada each year. Overall, this research provides new insights into the prevalence and trends of substance use during pregnancy, and aims to guide future public education initiatives and highlight the continuing need for more effective, accessible treatment options for pregnant women who struggle with substance use.Ph.D