Abstract 16466: Total Number of Pregnancies and Atrial Fibrillation Risk: The Women’s Health Study
Introduction: Parity has been associated with an increased risk of cardiovascular disease (CVD), which is thought to be mediated by obesity and insulin resistance. However, the relationship between parity and atrial fibrillation (AF) remains unclear.
Methods: We examined 34,636 female health professionals aged ≥45 years and free of AF or CVD at baseline within the Women’s Health Study. Women were prospectively followed for development of new-onset AF, which was confirmed by medical record review. Cox proportional hazards models were used to evaluate the relationship between total number of pregnancies ≥6 months in duration (0-1 [referent], 2-3, 4-5, 6) and incident AF risk.
Results: During a median follow-up of 19.2 years, 1467 women developed incident AF. Median baseline age was 52.9 [IQR 48.9, 58.8] years. In multivariable analyses (Table), after adjustment for multiple confounders, including measures of socioeconomic status, hazard ratios (HR) and 95% confidence intervals (95%CI) for incident AF across categories of increasing total number of pregnancies were 1.0, 1.12 (0.94 - 1.33), 1.26 (1.04 - 1.53), and 1.37 (1.06 - 1.76). Further adjustment for time-updated changes in body mass index (BMI), hypertension, diabetes, hypercholesterolemia and other variables did not have a significant impact on these associations. Adjustment for CVD events occurring during follow-up did not significantly alter these results (fully adjusted HRs and 95%CIs across pregnancy categories: 1.0, 1.11 (0.93 - 1.32), 1.25 (1.03 - 1.52), 1.35 (1.05- 1.74); p for linear trend=0.005).
Conclusions: In this large prospective cohort, number of prior pregnancies was directly associated with subsequent AF risk among women over age 45. This risk was not mediated by non-fatal CVD events, obesity, and/or diabetes. Repeated exposure to metabolic, physiological and/or hormonal changes during pregnancy may predispose to AF in later life and requires further investigation.
Author Disclosures: J.A. Wong: None. K.M. Rexrode: None. R.K. Sandhu: None. D. Conen: None. C.M. Albert: None.
- © 2015 by American Heart Association, Inc.