Add Health data connect young women’s pregnancy loss to their risk factors for cardiovascular disease

According to the American Heart Association, cardiovascular disease (CVD) is the leading cause of death for women worldwide. In this PLOS One article, authors Cortés et al. note that one of several female-specific risk factors for CVD is pregnancy loss, possibly associated with the metabolic and hormonal changes that can accompany pregnancy. Recent studies indicate that experiencing pregnancy loss can increase the risk of cardiovascular disease (CVD) later in life. However, not many studies have examined the impact of pregnancy loss on CVD risk factors in early adulthood (below the age of 35). So Cortés et al. set out to do so. They investigated the connection between pregnancy loss and CVD risk factors such as body mass index (BMI), blood pressure, hyperlipidemia (high cholesterol), and diabetes in early adulthood using data from the National Longitudinal Study of Adolescent to Adult Health (Add Health), 1994-2018 [Public Use] (ICPSR 21600). Add Health, one of ICPSR’s most downloaded studies, is made available by Data Sharing for Demographic Research (DSDR), which distributes Waves I-V of the public-use data. Developed in response to a mandate from the US Congress to fund a study of adolescent health, its first wave was fielded in 1994 and 1995, with a nationally representative sample of over 20,000 adolescents between the ages of 12 and 18. Waves I and II focused on the forces influencing their health and risk behaviors. Wave III explored their decisions, behavior, and health outcomes in the transition to adulthood. Wave IV expanded to examine developmental and health trajectories across their life course from adolescence into young adulthood, collecting social, behavioral, and biomedical data. And Wave V aimed to track the emergence of chronic disease as the cohort aged into their 30s and early 40s.

Cortés et al. conducted a cross-sectional analysis using data collected in Wave IV, which took place between 2007 and 2009, when participants were between 24 and 32 years old. The analytic sample they used consisted of the 2,943 individuals who had been pregnant at least once, and for whom complete biological data had been collected. The authors categorized pregnancy loss in three ways: no loss, one loss, or recurrent (two or more) losses, including both miscarriages and stillbirths. They then examined the relationships between pregnancy loss and each CVD risk factor, while accounting for sociodemographic characteristics, parity (number of children), health behaviors during pregnancy, and depression. They also tested for any differences based on race/ethnicity. Among the participants, 670 women reported experiencing a pregnancy loss, with 28 percent of them having had recurrent losses. Cortés et al. showed that a prior pregnancy loss was associated with a higher BMI (body mass index) specifically in non-Hispanic Black women, but not in white women. Additionally, women with recurrent pregnancy loss were more likely to have prediabetes compared to women who had only experienced live births. Overall, Cortés et al. found that experiencing pregnancy loss may contribute to a higher risk profile for cardiovascular disease in early adulthood, particularly for women who have had recurrent losses. These results support assessing CVD risk at younger ages, especially after a pregnancy loss, in order to safeguard future cardiovascular health.