Long-term mortality risk and life expectancy following recurrent hypertensive disease of pregnancy

Abstract

Women with a history of hypertensive disease of pregnancy have increased risks for early mortality from multiple causes. The effect of recurrent hypertensive disease of pregnancy on mortality risk and life expectancy is unknown. We sought to determine whether recurrent hypertensive disease of pregnancy is associated with increased mortality risks. In this retrospective cohort study, we used birth certificate data to determine the number of pregnancies affected by hypertensive disease of pregnancy for each woman delivering in Utah from 1939 through 2012. We assigned women to 1 of 3 groups based on number of affected pregnancies: 0, 1, or ≥2. Exposed women had ≥1 affected singleton pregnancy and lived in Utah for ≥1 year postpartum. Exposed women were matched 1:2 to unexposed women by age, year of childbirth, and parity. Underlying cause of death was determined from death certificates. Mortality risks by underlying cause of death were compared between exposed and unexposed women as a function of number of affected pregnancies. Cox regressions controlled for infant sex, gestational age, parental education, ethnicity, and marital status. We identified 57,384 women with ≥1 affected pregnancy (49,598 women with 1 affected pregnancy and 7786 women with ≥2 affected pregnancies). These women were matched to 114,768 unexposed women. As of 2016, 11,894 women were deceased: 4722 (8.2%) exposed and 7172 (6.3%) unexposed. Women with ≥2 affected pregnancies had increased mortality from all causes (adjusted hazard ratio, 2.04; 95% confidence interval, 1.76-2.36), diabetes (adjusted hazard ratio, 4.33; 95% confidence interval, 2.21-8.47), ischemic heart disease (adjusted hazard ratio, 3.30; 95% confidence interval, 2.02-5.40), and stroke (adjusted hazard ratio, 5.10; 95% confidence interval, 2.62-9.92). For women whose index pregnancy delivered from 1939 through 1959 (n= 10,488), those with ≥2 affected pregnancies had shorter additional life expectancies than mothers who had only 1 or 0 hypertensive pregnancies (48.92 vs 51.91 vs 55.48 years, respectively). Hypertensive diseases of pregnancy are associated with excess risks for early all-cause mortality and some cause-specific mortality, and these risks increase further with recurrent disease.