Blood Pressure Genetic Risk and Incident Hypertension at 2 to 7 Years Post Partum

Importance Hypertensive disorders of pregnancy (HDP; ie, preeclampsia/eclampsia and gestational hypertension) are associated with earlier development of chronic hypertension. Whether genetic risk for high systolic blood pressure (SBP) can stratify risk of new-onset hypertension after pregnancy is unclear. Objective To test the association of genetic risk for high SBP with new-onset hypertension at 2 to 7 years after delivery, independent of clinical characteristics and HDP history. Design, Setting, and Participants This was a cohort study of women enrolled during pregnancy between 2010 and 2013 and followed up at 2 to 7 years post partum. Included in the study were genotyped participants without pregestational chronic hypertension in the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (nuMoM2b) Heart Health Study. The setting included 8 US clinical sites. Study data were analyzed from October 2024 to January 2026. Exposures SBP genetic risk was calculated using a genome-wide SBP polygenic score and categorized as low (bottom quintile), intermediate (quintiles 2-4) or high (top quintile). Main Outcomes and Measures The primary outcome was stage 1+ hypertension (≥130/80 mm Hg or use of antihypertensive medication) at 2 to 7 years post partum. Logistic regression tested the association of SBP genetic risk with development of hypertension, adjusted for sociodemographic factors, prepregnancy diabetes, first-trimester BP, HDP history, and postpartum body mass index (BMI). Key secondary analyses were stratified by HDP history and compared population attributable risk for high SBP genetic risk, HDP history, and postpartum BMI. Results Among 2852 participants (mean [SD] age, 30.8 [5.5] years; 353 [12.4%] with prior HDP), 509 (17.8%) developed hypertension by 2 to 7 years (mean [SD], 3.2 [0.9] years) after delivery. SBP genetic risk was independently associated with incident hypertension (high vs low SBP genetic risk: adjusted odds ratio [aOR], 1.50; 95% CI, 1.09-2.07; P  = .01). In stratified analyses, SBP genetic risk was associated with incident hypertension in those without prior HDP (aOR, 1.25; 95% CI, 1.12-1.40 per SD; P  < .001) but not in those with prior HDP (aOR, 1.01; 95% CI, 0.79-1.28 per SD; P  = .92; P for interaction = .10). High SBP genetic risk, HDP history, and BMI greater than or equal to 25 (calculated as weight in kilograms divided by height in meters squared) accounted for 4.7%, 10.8%, and 41.5%, respectively, of population attributable risk for hypertension. Conclusions and Relevance Results of this cohort study reveal that higher SBP genetic risk was independently associated with higher risk of developing new-onset hypertension 2 to 7 years after delivery. However, HDP history and elevated BMI were more important contributors to hypertension risk.