Risk Factors Associated with Congenital Heart Defects: A Population-based Study

Background: Congenital heart defects (CHDs) are the most common heart defects and the leading cause of infant mortality and yet the cause of most CHDs is unknown. Few studies have examined the association between mother’s nativity and CHDs.

Methods: We conducted a population-based retrospective study of 10,206 children from Nevada birth defects registry for the period  2005 and 2011. Nevada birth defects registry is statewide  and uses active case ascertainment of birth defects. Birth defects data was linked to birth certificate data in order to get additional parental variables such as nativity and others that are not available in the birth defects data. We used Poisson regression models to analyze associations between mother’s nativity and select maternal and infant characteristics.

 Results: A total o f 3,226 (31.6%) children had CHDs. Maternal nativity of these infants was 66.8% US-born, 18.1% Mexico-born, and 15.1% were born in other parts of the world. The risk of having CHDs was lower among US-born mothers compared to Mexico-born mothers [relative risk = 0.82; 95% CI (0.79, 0.88)]. Other risk factors include increased maternal age [relative risk = 2.12; 95% CI (2.02, 2.38)] and maternal education [relative risk = 1.67; 95% CI (1.57, 1.80)].

 Conclusion

US-born mothers are at a lower risk of having children with CHDs compared to their Mexico-born. The differences might reflect variations in predisposition, cultural norms, and behavioral characteristics.