Grant: Project Grant

Congenital anomalies (birth defects) are the leading cause of infant death in Canada and can cause lifelong health problems for children who survive. Monitoring these conditions is essential for understanding population health and for evaluating the safety of medications, vaccines, and environmental exposures during pregnancy. However, current birth records in Canada only include pregnancies that end at or after 20 weeks, meaning they miss pregnancies affected by serious anomalies that are diagnosed and terminated earlier. As prenatal screening and genetic testing have improved, more anomalies are detected earlier in pregnancy, so an increasing number of affected pregnancies are missing from routine health data. This leads to underestimation of the true burden of congenital anomalies and may limit our ability to detect harmful exposures. This study aims to address this gap by using existing provincial-level data to identify pregnancies with congenital anomalies that ended before 20 weeks. Using data from British Columbia, we will develop a method that uses information from billing records of physician visits, laboratory tests, and ultrasounds to identify these cases. We will then test how accurate this method is by comparing it to detailed clinical records from the province's specialized high-risk pregnancy service, which captures all early terminations for congenital anomalies. By developing and validating this approach, the study will improve how congenital anomalies are identified in population health data. This will lead to more accurate monitoring, better research on causes and outcomes, and stronger evidence to inform public health policy and prevention efforts across Canada.