High blood pressure during pregnancy is associated with future cardiovascular disease : an observational cohort study

Objectives: The study aimed to determine if having a hypertensive disorder of pregnancy (HDP) is a risk factor for future cardiovascular disease (CVD), independent of age and body mass index (BMI). Design: Data were sourced from the baseline questionnaire of the 45 and Up Study, Australia, an observational cohort study. Setting: Participants were randomly selected from the Australian Medicare Database within New South Wales. Participants: A total of 84 619 women were eligible for this study, of which 71 819 were included. These women had given birth between the ages of 18 and 45 years, had an intact uterus and ovaries, and had not been diagnosed with high blood pressure prior to their first pregnancy. Results: HDP was associated with higher odds of having high blood pressure (<58 years: adjusted OR 3.79, 99% CI 3.38 to 4.24; p<0.001 and ≥58 years: 2.83, 2.58 to 3.12; p<0.001) and stroke (<58 years: 1.69, 1.02 to 2.82; p=0.008 and ≥58 years: 1.46, 1.13 to 1.88; p<0.001) in later life. Women with HDP had a younger age of onset of high blood pressure (45.6 vs 54.8 years, p<0.001) and stroke (58 vs 62.5 years, p<0.001). Women who had HDP and whose present day BMI was <25 had significantly higher odds of having high blood pressure, compared with women who were normotensive during pregnancy (<58 years: 4.55, 3.63 to 5.71; p<0.001 and ≥58 years, 2.94, 2.49 to 3.47; p<0.001). Women who had HDP and a present day BMI≥25 had significantly increased odds of high blood pressure (<58 years: 12.48, 10.63 to 14.66; p<0.001 and ≥58 years, 5.16, 4.54 to 5.86; p<0.001), compared with healthy weight women with a normotensive pregnancy. Conclusions: HDP is an independent risk factor for future CVD, and this risk is further exacerbated by the presence of overweight or obesity in later life.