Lower Socioeconomic Status is Associated with an Increased Incidence and Spectrum of Major Congenital Heart Disease and Associated Extracardiac Pathology

Several studies have suggested an inverse relationship between lower socioeconomic status (SES) and the incidence of congenital heart disease (CHD) among live births. We sought to examine this relationship further in a Canada-wide population study, exploring CHD subtypes, trends, and associated noncardiac abnormalities. Infants born in Canada (less Quebec) from 2008 to 2018 with CHD requiring intervention in the first year were identified using ICD-10 codes through the Canadian Institute for Health Information Discharge Abstract Database. Births of CHD patients were stratified by SES (census-based income quintiles) and compared against national birth proportions using X₂ tests. Proportions with extracardiac defects (ED) and nonlethal genetic syndromes (GS) were also explored. From 2008 to 2018, 7711 infants born with CHD were included. The proportions of major CHD distributed across SES quintiles were 27.1%, 20.1%, 19.2%, 18.6%, and 15.0% from lowest to highest, with significant differences relative to national birth proportions (22.0%, 20.0%, 20.6%, 20.7%, and 16.7% from lowest (1) to highest (5)) (p < 0.0001). No temporal trends in the CHD proportions across SES categories were observed over the study period. The distribution across SES quintiles was different only for specific CHD subtypes (double-outlet right ventricle (n = 485, p = 0.03), hypoplastic left heart syndrome (n = 547, p = 0.006), heterotaxy (n = 224, p = 0.03), tetralogy of Fallot (n = 1007, p = 0.008), truncus arteriosus (n = 126, p < 0.0001), and ventricular septal defect (n = 1916, p < 0.0001)), with highest proportions observed in the lowest quintile. The proportion of the total population with ED but not GS was highest in lower SES quintiles (< 0.0001) commensurate with increased proportion of CHD. Our study suggests a negative association between SES and certain CHD lesions and ED.