OBJECTIVE:To estimate the incidence of severe chronic hypertension (cHTN) within 5-7 years after a pregnancy complicated by mild cHTN.METHODS:This was a retrospective cohort study of women with mild cHTN during an index pregnancy between 2012 and 2014. Women were included if they received prenatal care at a single academic center and had mild cHTN during their pregnancy. Women with severe cHTN, type 1 diabetes, systemic lupus erythematosus, cardiomyopathy, proteinuria, or creatinine level greater than 1.1 mg/dL before 23 weeks of gestation at baseline were excluded. The primary outcome was a composite of severe cHTN (defined as new-onset of two or more severe blood pressures) or new-onset cardiovascular disease complications more than 12 weeks after the index delivery.RESULTS:A total of 647 women with mild cHTN met inclusion criteria. Of these, 236 (36.5%, 95% CI 32.8-40.2%) women experienced the primary composite outcome of severe cHTN within 5-7 years of the index pregnancy. Black women progressed more rapidly than White women (adjusted hazard ratio [aHR] 1.99, 95% CI 1.43-2.76). Smoking tobacco was also associated with more rapid progression to severe cHTN (aHR 1.47, 95% CI 1.13-1.90).CONCLUSION:In this cohort, one in three women with mild cHTN in an index pregnancy progressed to severe cHTN within 5-7 years. Prospective studies to validate this finding are needed.
