Miscarriage and future maternal cardiovascular disease: a systematic review and meta-analysis

CONTEXT: The 2011 American Heart Association guidelines identified pregnancy complications as a risk factor for cardiovascular disease in women. However, miscarriage was not mentioned within the guidelines, and there is no consensus on the association between miscarriage and future risk of cardiovascular disease. OBJECTIVE: To confirm or refute the association, a meta-analysis of published papers was conducted. DATA SOURCES: PubMed, Web of Knowledge and Scopus were systematically searched to identify appropriate articles. Reference lists were then hand searched for additional relevant titles. STUDY SELECTION: To be included, articles had to assess the association between miscarriage and subsequent cardiovascular disease in otherwise healthy women. Only women who had miscarriages were considered exposed. Pooled association measures, using random effects meta-analysis, were calculated for coronary heart disease and cerebrovascular disease. Publication bias and between-study heterogeneity were evaluated. DATA EXTRACTION: Two authors individually reviewed all studies and extracted data on patient and study characteristics along with cardiovascular outcomes. RESULTS: 10 studies were identified, with 517 504 individuals included in the coronary heart disease meta-analysis and 134 461 individuals in the cerebrovascular disease analysis. A history of miscarriage was associated with a greater odds of developing coronary heart disease, OR (95% CI) =1.45 (1.18 to 1.78), but not with cerebrovascular disease, OR=1.11 (0.72 to 1.69). There was a strong association between recurrent miscarriage and coronary heart disease OR=1.99 (1.13 to 3.50). Evidence was found for moderate between-study heterogeneity and publication bias in the coronary heart disease analysis. CONCLUSIONS: The meta-analysis indicates that a history of miscarriage or recurrent miscarriage is associated with a greater risk of subsequent coronary heart disease.