Effects of Selected Maternal Risk Factors on Congenital Heart Defects in Philadelphia 2003-2013

Abstract

Background: The primary aim of this study was to examine selected maternal risk factors (i.e. maternal cigarette smoking prior to or during pregnancy, maternal age, and pre-pregnancy obesity) and the risk of congenital heart defects (CHD). We hypothesized that maternal cigarette smoking prior to or during pregnancy, increased maternal age, and obesity are maternal risk factors associated with an increased risk of CHD. The secondary aim was to examine the trend of CHD among residents of Philadelphia from 2003-2013. Methods: We examined de-identified PA birth certificate records from 2003-2013 and found 213 confirmed cases of CHD. A random sample of 5 controls per case were selected to produce a more balanced design given the small number of cases, resulting in a total number of 1293 subjects. Randomly selected controls reflected all pregnancies that did not result in a heart defect. We modeled the independent association between the selected risk factors and CHD using logistic regression. Results: Findings suggest a role of maternal race and age related to CHD risk. Black mothers were less likely than white mothers to experience a CHD (OR=0.692; 95% CI, 0.493-0.971). Young mothers (< 20) were more likely to experience a CHD compared to women over 20 years old (OR=1.536; 95% CI, 0.270-1.062). A link between CHD and obesity and smoking were not found. The trend analysis showed a small, positive linear association among race and CHD cases overall. Clinical Relevance: We provided further evidence that maternal age and race are risk factors for CHD. The prevalence of congenital heart defects is increasing among Philadelphia residents. These findings could be a result of better diagnosis and reporting, but the increase may also be due to other risk factors in the population. These findings may have implications for further and more aggressive counseling before and during pregnancy.