Impact of Obesity on Outcomes of Pregnancy in Women With Heart Disease

Women with heart disease are at risk for complications during pregnancy. This study sought to examine the effect of maternal obesity on pregnancy complications in women with heart disease. The objective was to determine the incidence of adverse cardiac events (CE) in pregnant women with heart disease and obesity. Adverse CE during pregnancy were examined in a prospective cohort of women with heart disease. CE were a composite of the following: cardiac death/arrest, arrhythmias, heart failure, myocardial infarction, stroke, aortic dissection, and thromboembolic events. Pre-eclampsia and post-partum hemorrhage were also studied. Outcomes were examined according to body mass index (BMI). To identify additional predictors of CE, a baseline risk score (CARPREG [Canadian Cardiac Disease in Pregnancy Study] II score) for predicting cardiac complications was calculated for all pregnancies and included in a multivariable logistic regression model. Of 790 pregnancies, 19% occurred in women with BMI ≥30 kg/m2 (obesity), 25% in women with BMI 25 to 29.9 kg/m2 (overweight), 53% in women with BMI 18.5 to 24.9 kg/m2 (normal weight), and 3% in women with BMI <18.5 kg/m2 (underweight). Women with obesity were at higher risk of CE when compared with women with normal weight (23% vs. 14%; p = 0.006). In a multivariable model, obesity (odds ratio: 1.7; 95% confidence interval: 1.0 to 2.7) and higher CARPREG II risk scores (odds ratio: 1.7; 95% confidence interval: 1.5 to 1.9) predicted CE. Pre-eclampsia was more frequent in women with obesity compared with those with normal weight (8% vs. 2%; p = 0.001). Obesity increases the risk of maternal cardiovascular complications in pregnant women with heart disease. This modifiable risk factor should be addressed at the time of preconception counseling.