Maternal Risk of Cardiovascular Disease After Use of Assisted Reproductive Technologies.

Importance: The use of assisted reproductive technologies (ARTs) is steadily increasing worldwide. The outcomes associated with treatment for an individual's long-term health, including risk of cardiovascular disease (CVD), remain largely unknown, due to the small number of studies and their limited follow-up time. Objective: To study whether the risk of CVD is increased among individuals who have given birth after ART compared with those who have given birth without ART. Design, Setting, and Participants: A registry-based cohort study was conducted using nationwide data from Denmark (1994-2014), Finland (1990-2014), Norway (1984-2015), and Sweden (1985-2015). Data analysis was conducted from January to August 2022. A total of 2 496 441 individuals with a registered delivery in the national birth registries during the study period were included, and 97 474 (4%) of these gave birth after ART. Exposures: Data on ART conception were available from ART quality registries and/or medical birth registries. Main Outcomes and Measures: Information on CVD was available from patient and cause of death registries. The risk of CVD was estimated with Cox proportional hazards regression, adjusting for age, calendar year of start of follow-up, parity, diagnosis of polycystic ovary syndrome, diabetes, chronic hypertension, and country. Results: Median follow-up was 11 (IQR, 5-18) years. The mean (SD) age of women with no use of ART was 29.1 (4.9) years, and the age of those who used ART was 33.8 (4.7) years. The rate of any CVD was 153 per 100 000 person-years. Individuals who gave birth after using ART had no increased risk of CVD (adjusted hazard ratio [AHR], 0.97; 95% CI, 0.91-1.02), with evidence of heterogeneity between the countries (I2 = 76%; P = .01 for heterogeneity). No significant differences in the risk of ischemic heart disease, cerebrovascular disease, stroke, cardiomyopathy, heart failure, pulmonary embolism, or deep vein thrombosis were noted with use of ART. However, there was a tendency for a modest reduction in the risk of myocardial infarction (AHR, 0.80; 95% CI, 0.65-0.99), with no notable heterogeneity between countries. Conclusions and Relevance: The findings of this study suggest that women who gave birth after ART were not at increased risk of CVD over a median follow-up of 11 years compared with those who conceived without ART. Longer-term studies are needed to further examine whether ART is associated with higher risk of CVD.