Association between miscarriage and cardiovascular disease in a Scottish cohort

OBJECTIVE: To assess if miscarriage, whether consecutive or not, is associated with an increased risk of subsequent cardiovascular disease. METHODS: A cohort study was performed using women with at least one miscarriage or live birth recorded from 1950 to 2010 in the Aberdeen Maternity and Neonatal Databank. The exposed groups consisted of women with non-consecutive, two consecutive or three or more consecutive miscarriages; the unexposed group consisted of all women with at least one live birth and no miscarriages. Women were linked to Scottish Morbidity Records for hospital admissions for cardiovascular conditions, cardiac surgery and death registrations. Main outcome measures were ischaemic heart disease, cerebrovascular disease and a composite outcome of any disease of circulatory system. A sensitivity analysis was performed dividing the women into those who had one, two or three or more miscarriages irrespective of whether these events were consecutive or not. RESULTS: After excluding women with pre-existing hypertension, type 1 diabetes mellitus, kidney disease and 'disease of circulatory system', 60,105 women were analysed; 9419 with non-consecutive, 940 with two consecutive, 167 with three or more consecutive miscarriages and 49,579 with no miscarriage. In the multivariate analyses, a significant association was found between ischaemic heart disease and women with two (HRs 1.75 (95% CI 1.22 to 2.52)) or three or more (HR 3.18 (95% CI 1.49 to 6.80)) consecutive miscarriages. Similar patterns of risk were observed in the sensitivity analysis. CONCLUSION: Women with a history of two or more miscarriages, irrespective of whether consecutive or not, appear to have an increased risk of ischaemic heart disease.