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 - 2010 in the Aberdeen Maternity and Neonatal Databank. The exposed groups consisted of women with non-consecutive, two consecutive or ≥ three 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 ischemic 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 miscarriages irrespective of these were consecutive or not.

Results After excluding women with pre-existing hypertension, type one diabetes mellitus, kidney disease and ‘disease of circulatory system’, 60105 women were analysed; 9419 with non-, 940 with two, 167 with ≥ three consecutive miscarriages and 49579 with no miscarriage. In the multivariate analyses a significant association was found between ischemic heart disease and women with two {Hazard Ratios (HR) 1.75 (95% confidence interval (CI) 1.22-2.52-1.72)} or ≥ three {HR 3.18 (95%CI 1.49-6.80-4.51)} consecutive miscarriages. Similar patterns of risk were observed in the sensitivity analysis.

Conclusions Women with a history of two or more miscarriages, irrespective of whether consecutive or not, appear to have an increased risk of ischemic heart disease.