A nationwide population-based cohort study based in Sweden found that women who experienced adverse pregnancy outcomes and their sisters who did not both faced increased long-term cardiovascular disease risks.
Researchers followed over 1.2 million primiparous women between 1992 and 2019, highlighting familial factors that may contribute to cardiovascular (CVD) development.
According to findings from the study, published in the European Heart Journal, women with adverse pregnancy outcomes (APOs) exhibited a two-fold increased rate of major adverse cardiac events (MACE) compared to unrelated APO-free comparators (adjusted hazard ratio [aHR] = 2.33; 95% confidence interval [CI] = 2.08–2.61). Their APO-free sisters also demonstrated elevated risks of MACE, with full sisters showing a 34% increased rate (aHR = 1.34; 95% CI = 1.05–1.71) and half-sisters, a 55% increase (aHR = 1.55; 95% CI = 1.07–2.24).
The incidence of ischemic heart disease (IHD) was also notably higher in this population, with APO-exposed women exhibiting a two-fold increase in IHD risk (aHR = 2.19; 95% CI = 1.63–2.95). Heart failure rates were also substantially elevated, showing a 3.5 times higher occurrence among APO-exposed women (aHR = 3.54; 95% CI = 2.92–4.31). Additionally, cerebrovascular events occurred at a two-fold increased rate in APO-exposed women (aHR = 1.89; 95% CI = 1.62–2.21); in comparison, APO-free full sisters experienced a 44% increase in cerebrovascular events (aHR = 1.44; 95% CI = 1.07–1.94).
The results suggest a genetic and/or environmental influence on the association between APOs and CVDs, wrote the study authors. The findings indicate that APO history could serve as a marker for future CVD risk, not only in affected women but also in their siblings.
"Our study underscores the contribution of familial factors, encompassing genetic predisposition and environmental influences, to the heightened risk of CVD among women with APOs," wrote first author Ängla Mantel, MD, PhD, of the Department of Medicine Solna, Clinical Epidemiology Division at the Karolinska Institute, and colleagues.
"Notably, APOs emerged as potential triggers for CV events in predisposed individuals, resulting in a rapid escalation of CVD risk, particularly pronounced in APO-exposed women and, albeit to a lesser extent, in their APO-free sisters," they added.
This large-scale study utilized high-quality national health registers, allowing for extensive follow-up. However, limitations of the study included a lack of genetic data and exclusion of non-Nordic populations, potentially affecting generalizability, noted investigators.
No conflicts of interest were disclosed.