During pregnancy, approximately 15 per cent of women experience depression requiring medical intervention. Although these conditions are often treated with Serotonin Reuptake Inhibitor (SRI) antidepressants, these drugs are reported to increase the risks of adverse infant outcomes, including preterm birth, small for gestational age (SGA) birth, respiratory distress, and some congenital heart malformations. Infant outcomes are also influenced by other factors, including socioeconomic status, and research has shown that mothers of lower socioeconomic status are at increased risk of preterm birth, SGA birth, stillbirth, and neonatal and infant death. To complicate things further, data shows that mothers of low socioeconomic status are significantly more likely to experience depression during pregnancy and are significantly more likely to use one or more psychotropic medications (including antidepressants) to manage mental illness during pregnancy than women of higher income. The relationships between prenatal depression, socioeconomic status, use of antidepressants, and infant outcomes are complex and poorly understood.
Dr. Gillian Hanley will systematically address questions about the role socioeconomic status plays in maternal depression, antidepressant use, and infant developmental outcomes during the first year of life. She has hypothesized that maternal socioeconomic status accounts for an increased risk of adverse infant outcomes previously attributed to antidepressant exposure during pregnancy. For this study, Dr. Hanley will link a number of BC population-level administrative datasets to build the most comprehensive source of data on pregnant women of its kind in the world. This dataset will include all pregnancies and births in British Columbia between 2002 and 2009 (approximately 300,000 infants) and will provide sufficient sample size to detect differences in rare outcomes, such as congenital anomalies and neonatal/infant death. In this project, socioeconomic status will be studied as a predictor of antenatal maternal depression, antidepressant use, and infant developmental health.
These results will illuminate complex relationships between prenatal depression, antidepressant use, and infant outcomes. Given that it is ethically and medically unadvisable to undertake a randomized trial of prenatal antidepressant exposure, this population-based study will provide an unprecedented opportunity to examine key influences on infant health. Dr. Hanley's findings should help clinicians and mothers make more informed treatment decisions for their health and that of their infants.