Is Number of Pregnancies a Risk Factor for Heart Attack in Women?

Background: Studies regarding number of pregnancies and coronary heart disease have shown inconsistent results. In the present study, we assessed the association between number of pregnancies and heart attack (HA) in women.Methods: Using data from NHANES III a cross sectional data analysis of 10634 women aged 17 and above was conducted. We considered socio-demographic factors and other potential risk factors including physical activity, smoking, alcohol, diabetes, hypertension, hypercholesterolemia, BMI, age, and family history of heart attack. We conducted Bivariate analysis to determine prevalence and crude odds ratios. Multivariate logistic regression analysis was used to adjust for confounding variables using SPSS. Results: The prevalence and 95% CI of HA was 3.4% (3.0% – 3.7%). The age adjusted odds ratios for 7+ pregnancies was 2.33 95% CI [1.42-3.81], but this became insignificant when a fully adjusted model was used (odds ratio, 1.68: 95% CI, 0.89 to 3.16). For those with 4 pregnancies the risk was lowest in both age adjusted and fully adjusted models confirming the well known "J" shaped non linear relationship between number of pregnancies and heart attack. Conclusion: We found an association that was not significant between number of pregnancies and heart attack. Further studies using physician-confirmed diagnosis is needed to appropriately asses the potential relationship of gravidity and heart attack.