Pregnancy loss and risk of cardiovascular disease: a prospective population-based cohort study (EPIC-Heidelberg)

OBJECTIVES: To examine whether pregnancy loss (miscarriage, abortion or stillbirth) is associated with a higher risk of myocardial infarction (MI) and stroke. DESIGN: Population-based prospective cohort study. SETTING: The European Prospective Investigation into Cancer and Nutrition (EPIC) cohort in Heidelberg, Germany (mean follow-up 10.8 years). PARTICIPANTS: All 11,518 women who had ever been pregnant (aged 35-66). RESULTS: Out of the participants, 2876 (25%) had at least one miscarriage, 2053 (18%) had at least one abortion and 209 (2%) had at least one stillbirth. During the follow-up, 82 cases of MI and 112 of stroke (confirmed by medical records) occurred in these women. Each stillbirth increased the risk of MI 2.65 times (95% CI for age-adjusted HR 1.37 to 5.12; HR adjusted for age, smoking, alcohol consumption, body mass index, waist to hip ratio, physical activity, education, number of pregnancies, hypertension, hyperlipidaemia and diabetes mellitus: HR 2.32 95% CI 1.19 to 4.50, 95% CI). Recurrent miscarriage (>3) was associated with about nine times higher risk of MI (age-adjusted HR = 8.90, 95% CI 3.18 to 24.90; fully adjusted HR 5.06, 95% CI 1.26 to 20.29). No significant association was found between abortion and MI or between any type of pregnancy loss and stroke. CONCLUSIONS: These results suggest that women who experience spontaneous pregnancy loss are at a substantially higher risk of MI later in life. Recurrent miscarriage and stillbirth are strong sex-specific predictors for MI and thus should be considered as important indicators for cardiovascular risk factors monitoring and preventive measures. Further research is suggested to elucidate underlying risk factors of pregnancy loss that at the same time strongly predispose to cardiovascular disease.