Association of Concomitant Gestational Hypertensive Disorders and Gestational Diabetes With Cardiovascular Disease.

Importance: Accruing evidence suggests that gestational hypertensive disorders (GHTD) and gestational diabetes (GD) are each associated with an increased risk of cardiovascular disease (CVD). However, the extent to which the co-occurrence of GHTD and GD is associated with the risk of CVD remains largely unknown. Objective: To estimate the individual and joint associations of GHTD and GD with incident CVD. Design, Setting, and Participants: This population-based cohort study used the Ministry of Health and Long-Term Care of Ontario (Canada) health care administrative databases. All women in Ontario with a GHTD and/or GD diagnosis, and a live-birth singleton delivery between July 1, 2007, and March 31, 2018, were considered for inclusion. Women with pregravid diabetes, hypertension, or cardiovascular disease were excluded. Statistical analysis was performed from November 2021 to September 2022. Exposures: GD and/or GHTD, defined using diagnosis coding. Main Outcomes and Measures: Individual and joint associations of GHTD and GD with incident CVD (including a composite of myocardial infarction, acute coronary syndrome, stroke, coronary artery bypass grafting, percutaneous coronary intervention, or carotid endarterectomy), estimated using Cox regression models, adjusting for relevant cardiometabolic risk factors. The follow-up extended from the index pregnancy until March 31, 2020. Results: Among 886 295 eligible women (mean [SD] age, 30 [5.6] years; 43 861 [4.9%] with isolated GHTD, 54 061 [6.1%] with isolated GD, and 4975 [0.6%] with GHTD and GD), there were 1999 CVD events over 12 years of follow-up. In the early postpartum phase (first 5 years post partum), there was no association of co-occurrence of GTHD and GD (adjusted hazard ratio [aHR], 1.42, 95% CI, 0.78-2.58) or GD alone (aHR, 0.80; 95% CI, 0.60-1.06) with CVD; there was an association between isolated GTHD and incident CVD compared with no GTHD and no GD (aHR, 1.90; 95% CI, 1.51-2.35). In the late postpartum period (after the initial 5 years post partum), compared with no GD and no GHTD, isolated GHTD (aHR, 1.41, 95% CI, 1.12-1.76) and co-occurrence of GHTD and GD (aHR, 2.43, 95% CI, 1.60-3.67) were each associated with a higher risk of incident CVD. There was no association between isolated GD and incident CVD. Conclusions and Relevance: In this cohort study, GHTD was associated with a high risk of CVD post partum, and the co-occurrence of GD and GHTD was associated with a much greater postpartum CVD risk. These findings suggest that CVD preventive care is particularly needed in the aftermath of combined GD and GHTD.