Number of Pregnancies and Risk of Atherosclerotic Cardiovascular Disease in Postmenopausal Women: A Cross-Sectional Study of NHANES from 1999 to 2018.

Background: Atherosclerotic cardiovascular disease (ASCVD) remains the most common cause of death in women. Pregnancy is an exposure unique to women leading to significant changes in maternal cardiovascular function. However, studies of the relationship between the number of pregnancies and ASCVD are rare. We aimed to clarify the association between the number of pregnancies and ASCVD. Methods: In this cross-sectional study, we used publicly available data from the National Health and Nutrition Examination Survey from 1999 to 2018. The number of pregnancies was divided into 0 (reference), 1, 2-3, 4-5, or ≥6, to create more stable estimates. A multiple logistic regression approach was used to examine the correlation between pregnancy and ASCVD in women aged 45 years or older who reported no menstruation in the past 12 months due to menopause, as well as in those aged 55 years or older, encompassing various age groups. We also separately estimated the association between the exposure of pregnancy and individual components of ASCVD. Results: In this study, age-adjusted data showed that women with six or more pregnancies had a doubled risk (odds ratio [OR]: 2.07) of ASCVD. The risk remained elevated at 1.69 times in women with four to five pregnancies and further increased to 1.90 times in women with six or more pregnancies, after adjusting for social factors. Similar patterns were observed when considering reproductive health and cardiovascular risk factors. Across the full population, every model that accounted for these variables consistently indicated that with an increasing number of pregnancies, we observed higher ORs for ASCVD risk (all p values <0.05). Conclusions: A higher number of pregnancies was associated with a higher risk of ASCVD after menopause, especially among women aged 45-64 years. Moreover, this association is particularly significant in the risk of stroke, cardiovascular heart disease, and heart attack.