Miscarriage and stillbirth in relation to risk of cardiovascular diseases: A systematic review and meta-analysis

Introduction: The relationship between pregnancy loss and the risk of cardiovascular diseases (CVDs) remains a matter of debate. Our intention in conducting this meta-analysis was to analyze the relationship between miscarriage and stillbirth and risk of CVDs. Methods: PubMed, Embase, and Web of Science were systematically searched up to May 30, 2023 for all relevant studies. The random-effects model was applied to estimate the pooled relative risks (RRs) and 95% confidence intervals (95% CIs). We evaluated RR estimates for the risk of CVDs with each additional miscarriage and stillbirth through generalized least squares regression. Results: Twenty-three articles were incorporated into the meta-analysis. For women with a history of miscarriage, the pooled RRs for the risk of total CVDs, coronary heart disease (CHD), stroke, and total CVD deaths were 1.16 (95 % CI 1.10-1.22), 1.26 (1.12-1.41), 1.13 (1.03-1.24), and 1.20 (1.01-1.42), respectively. For women with a history of stillbirth, the pooled RRs for the risk of total CVDs, CHD, stroke, and total CVD deaths were 1.60 (1.34-1.89), 1.30 (1.12-1.50), 1.37 (1.06-1.78), and 1.95 (1.05-3.63), respectively. With each additional miscarriage, the risk increased for total CVDs (1.08, 1.04-1.13), CHD (1.08, 1.04-1.13), and stroke (1.05, 1.00-1.10). With each additional stillbirth, the risk increased for total CVDs (1.11, 1.03-1.21) and CHD (1.13, 1.07-1.19). Conclusion: This meta-analysis indicates that both miscarriages and stillbirths are related to a higher risk of total CVDs, CHD, stroke, and total CVD deaths. The risk of total CVDs and CHD increased with the number of miscarriages or stillbirths.