Previous pre-eclampsia, gestational diabetes mellitus and the risk of cardiovascular disease: A nested case-control study in Sweden

Objective: Pre-eclampsia and gestational diabetes mellitus (GDM) are two common pregnancy complications that affect birth outcomes and are associated with a long-term risk of cardiovascular disease (CVD). The aims of this study were to investigate if the pre-eclampsia association with CVD is independent of GDM and modified by body mass index (BMI) or GDM. Design: Case-control study. Setting: Sweden. Population: Cases were women with a first CVD event between 1991 and 2008 and a previous pregnancy who were matched with controls without CVD (1:5) by year of birth, age and region of birth. Methods: Conditional logistic regression was used to evaluate the associations of GDM, pre-eclampsia and maternal BMI with CVD adjusted for potential confounders and effect modifications with interaction tests. Main outcome measures: CVD. Results: There were 2639 cases and 13 310 controls with complete data. Pre-eclampsia and GDM were independent risk factors for CVD (adjusted odds ratio [aOR] 2.59, 95% CI 2.12-3.17 and aOR 1.47, 95% CI 1.04-2.09, respectively). After stratifying by maternal BMI, the adjusted association of pre-eclampsia with CVD did not differ notably between BMI groups: normal weight (aOR 2.65, 95% CI 1.90-3.69), overweight (aOR 2.67, 95% CI 1.52-4.68) and obesity (aOR 3.03, 95% CI 0.74-12.4). Similar findings were seen when stratifying on GDM/non-GDM. Conclusions: Pre-eclampsia and GDM are independent risk factors for later CVD and having both during pregnancy is a major risk factor for later CVD. The association between pre-eclampsia and CVD is not modified by BMI. Effective CVD preventive programs for high--risk women are urgently needed in order to improve women's long-term health.