Risk factors of different congenital heart defects in Guangdong, China

Background: Limited studies have evaluated the risk factors for congenital heart defects (CHDs) in China and compared them for different types of CHDs. This study examined risk factors between isolated and multiple CHDs as well as among CHDs subtypes in Guangdong, Southern China. Methods: This population-based case–control study included 4,034 pairs of case and control infants enrolled in the Guangdong Registry of CHD study, 2004–2013. Multivariate logistic regression was used to compute adjusted odds ratios (ORs) while simultaneously controlling for confounders. Results: Multiple maternal environmental exposures, including living in newly renovated rooms, residential proximity to main traffic, paternal smoking, and maternal occupation as manual worker, were significantly associated with CHDs with ORs ranging 1.30–9.43. Maternal perinatal diseases (including maternal fever, diabetes, influenza, and threatened abortion), maternal medication use (antibiotic use), advanced maternal age, low socioeconomic status, and paternal alcohol intake were also significantly associated with CHDs, with ORs ranging 1.60–3.96. Isolated CHDs and multiple defects have different profiles of risk factors, while subtype of CHD shares common risk factors. Conclusion: These results suggest that maternal environmental exposures/occupation and perinatal diseases/medication use were dominant risk factors associated with CHDs in Southern China. Isolated and multiple CHDs may have different etiologic factors.