Infertility and the risk of cardiovascular disease: findings from the Study of Women’s Health Across the Nation (SWAN)

Abstract Background Cardiovascular disease is the leading cause of death in women globally. In recent years, attention has turned to infertility and pregnancy-related events as potential markers for early mortality and future cardiovascular disease. Methods The Study of Women’s Health Across the Nation is an ongoing longitudinal cohort study of women’s health. Women aged 42-52 with a uterus and ≤1 intact ovary, a menstrual period, and no hormone medications within three months prior to enrollment were eligible. Infertility was self-reported and defined as the inability to achieve pregnancy after 12 months of trying to conceive, or use of fertility medications for >1 month. Outcomes included development of metabolic syndrome over 7 years follow-up, and any atherosclerotic CVD event (i.e., stroke, angina, myocardial infarction) over 10 years follow-up. Cox proportional hazards models were used to calculate hazard ratios (HR) for metabolic syndrome and CVD events in participants with infertility, with adjustment for relevant covariates. Participants without infertility were used as the comparison group. Results 2,370 participants were included in the analysis of metabolic syndrome risk, and 2,809 participants were included in the analysis of CVD event risk. Participants with self-reported infertility did not have a higher risk of developing metabolic syndrome (HR=0.91, 95% CI 0.71-1.15) or experiencing CVD events (HR=0.79, 95% CI 0.52-1.21) after adjusting for relevant covariates. Conclusions Infertility was not associated with development of metabolic syndrome or CVD events in females; further research is required to investigate the effects of specific causes of infertility and fertility treatments on CVD outcomes.