Hypertension during pregnancy may impact CV health for life
Women with pre-eclampsia or gestational hypertension during their first pregnancy had an increased risk of developing chronic hypertension, type 2 diabetes (T2D), and hypercholesterolaemia than those who were normotensive during pregnancy, according to a study. The risk persisted for several decades later, signalling these hypertensive disorders of pregnancy (HDP) as red flags for cardiovascular (CV) health for life.
“Although the 2011 American Heart Association guidelines recommend that clinicians evaluate CVD risk by screening for a history of HDP, few data exist on which risk factors should be screened for as well as the frequency and timing of screening,” stated the researchers. [Circulation 2011;123:1243-1262]
The observational cohort study followed 58,671 parous participants (mean age 26.8 years) in the Nurses’ Health Study II without CVD or CVD risk factors of interest at baseline for self-reported physician-diagnosed chronic hypertension, hypercholesterolaemia, and T2D. Of these, 9.2 percent experienced 9.2 percent experienced HDP during the first pregnancy, 2.9 percent had gestational hypertension, and 6.3 percent had pre-eclampsia. [Ann Intern Med 2018;doi:10.7326/M17-2740]
Compared with normotensive women, those with gestational hypertension or pre-eclampsia during the first pregnancy were more than twice as likely to develop chronic hypertension during a mean follow-up of 25–32 years (hazard ratio [HR], 2.79, 95 percent confidence interval [CI], 2.6–3.0 and 2.21, 95 percent CI, 2.1–2.3 for gestational hypertension and pre-eclampsia, respectively).
These women also had a more than 60 percent higher risk of developing T2D (HRs, 1.65 and 1.75 for women with gestational hypertension and pre-eclampsia, respectively) and a more than 30 percent greater chance of developing hypercholesterolaemia (HRs, 1.36 and 1.31, respectively) than women who were normotensive during pregnancy.
Although the risk of developing the CVD risk factors remained elevated throughout the follow-up period, the relative risk was strongest in the first 5 years after the first delivery, particularly for chronic hypertension.
Furthermore, women with HDP developed the CVD risk factors at a younger age than those who were normotensive during pregnancy (p<0.001).
“This finding is both novel and important because it suggests that women with a history of HDP could benefit from CV risk assessment at an earlier age than those without HDPs,” wrote Dr Abigail Fraser of University of Bristol, UK, in an editorial. [Ann Intern Med 2018;doi:10.7326/M18-1443]
Also, recurrent HDP was associated with the highest rates of developing the CVD risk factors mentioned above, with women who had HDP in ≥2 initial pregnancies showing the highest risk for chronic hypertension (HR, 1.3, 95 percent CI, 1.2–1.5) and hypercholesterolaemia (HR, 3.5, 95 percent CI, 3.2–3.9) compared with women without HDP in ≥2 pregnancies.
Unlike previous studies with incomplete adjustment for potential prepregnancy confounders, the current study showed that rates of developing the CVD risk factors remained elevated with presence of HDP after adjusting for multiple potential confounders including age, ethnicity, physical activity, family history of hypertension or T2D, parental education, as well as prepregnancy and post-pregnancy behaviours such as smoking, alcohol consumption, and oral contraceptive use.
“It is not yet clear whether HDP unmasks pre-existing CV risk through the ‘stress test’ of pregnancy or whether it induces endothelial or organ damage that alters a woman’s trajectory toward development of CVD risk factors,” said the researchers.
“The nature of the relationship between pregnancy complications, such as HDP, and CVD has practical implications. If HDP increase CVD risk independently of prepregnancy CV health (for example, by causing end-organ damage), prevention of such complications has the potential to reduce the burden of CVD in women. If, on the other hand, prepregnancy CV health is key, prevention efforts should be aimed at young women before conception,” explained Fraser.