First trimester bleeding and maternal cardiovascular morbidity

First trimester bleeding without miscarriage is a risk factor for complications later in the pregnancy, such as preterm delivery. Also, first trimester miscarriage has been linked to subsequent maternal ischemic heart disease. We investigated the link between maternal cardiovascular disease prior to and subsequent to first trimester bleeding without miscarriage.

We performed a registry-based retrospective cohort study of 796,915 women who gave birth to a singleton infant after 20 completed weeks in Denmark in 1978-2007. The exposures and endpoints were registry diagnoses of cardiovascular diseases preceding pregnancy, first trimester vaginal bleeding without miscarriage, and subsequent maternal cardiovascular disease. In the adjusted models, we considered preterm delivery, prelabor rupture of membranes, hypertensive pregnancy disorders, fetal growth restriction, placental abruption and stillbirth as possible confounders. We used logistic regression and Cox proportional hazard models to assess the associations.

Women with pre-pregnancy cardiovascular disease had a 2.2-fold (95% CI 1.3-4.1) increased risk of first trimester bleeding without miscarriage, and first trimester bleeding without miscarriage was associated with a 1.6-fold (1.4-1.8) increase in risk of subsequent maternal ischemic hearth disease after adjusting for other adverse pregnancy outcomes.

First trimester bleeding without miscarriage is associated with pre-pregnancy as well as subsequent maternal cardiovascular morbidity.