Risk factors for isolated congenital heart defects in infants from Western Mexico

Congenital heart defects (CHDs) are caused by a complex interaction between numerous genetic and environmental risk factors, some of which may differ between different populations. A case-control study was conducted among 1232 newborns, including 308 patients with isolated CHDs (cases) and 924 infants without birth defects (controls), born all during the period 2009-2023 at the Hospital Civil de Guadalajara "Dr. Juan I. Menchaca" (Guadalajara, Mexico). Potential parental risk factors for CHDs were compared using multivariate logistic regression analysis to evaluate the deviance explained by different variables of interest. Consanguinity [adjusted odds ratio (aOR) = 3.3; 95% confidence interval (CI) 1.3-8.5], relatives with CHD (aOR = 8.5; 95% CI 5.3-13.8), maternal first-trimester exposure to diabetes (aOR = 3.5; 95% CI 2.4-5.1), hypertension (aOR = 2.6; 95% CI 1.5-4.4), alcohol consumption (aOR = 1.5; 95% CI 1.0-2.1), and illicit drug use (aOR = 2.4; 95% CI 1.2-5.3), as well as for the paternal history of alcohol consumption (aOR = 1.4; 95% CI 1.0-1.8) and illicit drug use (aOR = 2.7; 95% CI 1.7-4.1), were associated with CHDs. Contrarily, aOR for maternal age ≤19 years (aOR = 0.6; 95% CI 0.4-0.8) and maternal first-trimester coffee consumption (aOR = 0.7; 95% CI 0.5-0.9) have protective odds. Our results suggest that genetic factors, maternal diseases, environmental exposures, and reproductive factors can increase the occurrence of isolated CHDs in our sample, and they are discussed as clues in its pathogenesis.