Regional Variations in the Prevalence of Major Congenital Malformations in Quebec: The Importance of Fetal Growth Environment

摘要

Background Congenital anomalies are the consequence of a complex interaction between genetic predisposition and fetal environment. Based on the Congenital Anomalies Surveillance in Canada Report, between 1998 and 2007 the rate of congenital heart defects in Quebec was significantly higher than the Canadian average; no data on the overall prevalence of congenital anomalies for Quebec or data on regional variations in any province are available. Objectives To estimate the prevalence of major congenital malformations (MCMs) in all of the 17 administrative regions of Quebec. Methods Using data from the Quebec Pregnancy Cohort, we included infants if they were born between January 1, 1998 and December 31, 2008. MCMs were identified within the infant’s first year of life using validated ICD-9 and ICD-10 codes. The rate of MCMs was calculated and stratified on Quebec’s administrative regions. Results Among 152,353 eligible infants, the prevalence of MCMs was 36.6 (all rates were reported as per 1,000 live births). The regions with the highest rate of MCMs were Lanaudière (48.1), Laval (45.8), and Mauricie (45.1). Regions with the lowest rate were Outaouais (13.4), C?te-Nord (19.1), Abitibi-Témiscamingue (27.5), Gaspésie-?les-de-la-Madeleine (27.9), and Saguenay-Lac-Saint-Jean (28.9). Congenital heart defects (10.3) and musculoskeletal anomalies (12.6) were the most common. Laval had the highest rate of heart defects (16.1), and Lanaudière had the highest rate of musculoskeletal anomalies (22.0). Conclusions The central regions of Quebec had high rate of MCMs, whereas the relatively genetically homogenous peripheral regions of Quebec had lower rate of MCM, suggesting the importance of fetal growth environment in the etiology of MCMs in Quebec.