Pregnancy Hypertensive Disorders Increase Risk of Premature Death

Hypertensive disorders of pregnancy (HDPs), particularly gestational hypertension and preeclampsia, increase a woman’s risk of premature death, especially from cardiovascular disease, according to a study in the Journal of the American College of Cardiology. The risk remained even for women who were not diagnosed with chronic hypertension.

HDPs are one of the most frequent health challenges in pregnant women, occurring in about 10% of pregnancies throughout the world. The four categories of HDPs are gestational hypertension (GHTN), preeclampsia, chronic hypertension, and chronic hypertension with superimposed preeclampsia. Of these, preeclampsia and GHTN that occur at or after 20 weeks are leading causes of perinatal and maternal morbidity and mortality.

Jorge E Chavarro, MD, ScD, of the department of nutrition and the department of epidemiology, both at the Harvard T.H. Chan School of Public Health in Boston, Massachusetts and of the Channing Division of Network Medicine in the department of medicine at Brigham and Women's Hospital, Harvard Medical School also in Boston, served as lead author on the study. Chavarro and colleagues performed the study to examine the association between HDPs, particularly GHTN and preeclampsia, and a subsequent link to chronic hypertension and risk of premature death.

They examined data from 88,395 parous nurses between the ages of 25 and 42 who participated in the Nurse’s Health Study II between 1989-2017. This study collected data about lifestyle, health conditions, and reproductive characteristics over a period of 30 years. It focused on HDPs, particularly gestational hypertension and preeclampsia. Researchers used Cox proportional hazards models that were adjusted for relevant confounders to estimate confidence intervals and hazard ratios for connections between premature mortality and HDPs.

Using the Nurse’s Health Study II, the authors divided the women into 4 groups: no HDPs and chronic hypertension, HDPs only, chronic hypertension only, or both HDPs and subsequent chronic hypertension.

Researchers said 14% of women (12,405) had HDPs in at least one pregnancy. Of the 88,395 women in the study, 2,387 (2.7%) died before age 70 in 28 years of follow-up. Cancer accounted for 1,141 deaths, while CVD accounted for 212 deaths. According to the authors, during follow-up HDPs, either preeclampsia or GHTN was associated with a 1.31 hazard ratio for early death (95% CI: 1.18 to 1.46) and a 42% increase in premature death.

Researchers said the association remained even after adjusting for cofounders and for reproductive characteristics, diet, and lifestyle post-pregnancy. Women with preeclampsia and/or GHTN had a higher baseline BMI, chronic hypertension, gestational diabetes, and parental history of myocardial infarction/stroke.

“Relations were strongest for CVD-related mortality (HR: 2.26; 95% CI: 1.67 to 3.07). The association between HDPs and all-cause premature death persisted, regardless of the subsequent development of chronic hypertension (HR: 1.20 [95% CI: 1.02 to 1.40] for HDPs only and HR: 2.02 [95% CI: 1.75 to 2.33] for both HDPs and subsequent chronic hypertension),” researchers reported.¹

According to the authors, HDP had more than twice the risk of premature CVD mortality. For the development of chronic hypertension, researchers saw a higher risk of all-cause premature CVD mortality in HDPs-only patients, chronic hypertension alone, and both HDPs and subsequent chronic hypertension.

“Our results suggest that HDPs, either GHTN or preeclampsia, was associated with a greater risk of premature mortality, especially CVD-related deaths, even in the absence of chronic hypertension," Chavarro said in the AAAS press release. "Our results highlight the need for clinicians to screen for the history of HDPs when evaluating CVD morbidity and mortality risk of their patients."

This study adds to data that health conditions in pregnancy affect women throughout their lives. A study also published in the Journal of the American College of Cardiology found increased rates of cardiac complications in women with obesity versus women of normal weight.²

Candice Silversides, MD, of the division of cardiology at the University of Toronto’s Pregnancy and Heart Disease Program at Mount Sinai and Toronto General Hospitals in Toronto, Ontario, and co-author of this additional study said in the same AAP press release, "Pregnant women with heart disease and obesity should be educated about these risks, and health care providers should ensure that dietary advice, weight gain recommendations, and that obesity and other comorbidities are addressed as part of routine care.

"Postpartum surveillance is important in pregnant women with obesity because of the increased risk of complications during this time period," she added.

References

1. Wang YX, Arvizu M, Rich-Edwards JW, et al. Hypertensive disorders of pregnancy and subsequent risk of premature mortality. J Am Coll Cardiol. 2021;77(10):1302-1312. doi:10.1016/j.jacc.2021.01.018
2. Pfaller B, Siu SC, D'Souza R, et al. Impact of obesity on outcomes of pregnancy in women with heart disease. J Am Coll Cardiol. 2021;77(10):1317-1326. doi:10.1016/j.jacc.2021.01.010