Boston, MA — Preeclampsia and gestational hypertension are common pregnancy complications involving high blood pressure that develops for the first time during pregnancy and returns to normal after delivery. Previous studies have shown that women with high blood pressure during pregnancy are more likely to have a heart attack or stroke later in life compared to women with normal blood pressure during pregnancy. What is less clear is to what extent women are more likely to develop cardiovascular disease risk factors and when these risk factors begin to emerge after a hypertensive pregnancy, knowledge critical to inform screening guidelines.
In a new study, researchers from Brigham and Women’s Hospital and the Harvard T.H. Chan School of Public Health measured how often and when women with high blood pressure during pregnancy develop high blood pressure, diabetes, and high cholesterol after pregnancy. Results are published in Annals of Internal Medicine on July 3, 2018.
The research revealed that women who had high blood pressure during their first pregnancy were more likely than those with normal blood pressure to develop high blood pressure, diabetes, and high cholesterol after the pregnancy. In addition, the data showed that the risk factors for cardiovascular disease emerged shortly after pregnancy and persisted for decades.
“Preeclampsia and gestational hypertension are common pregnancy complications that can alert women and their health care providers about their future cardiovascular health,” stated Jennifer Stuart, ScD, postdoctoral research fellow at Brigham and Women’s Hospital and the Harvard T.H. Chan School of Public Health. “Women who experience preeclampsia or gestational hypertension should tell their doctor and adopt a heart healthy diet and lifestyle – just like they would if they had a family history of cardiovascular disease – to reduce cardiovascular risk and delay disease onset.”
This study was conducted among almost 60,000 women enrolled in the Nurses’ Health Study II who had given birth at least once. Women were studied for an average of 25 to 32 years after the first pregnancy – depending on the risk factor – but overall, follow-up ranged from two to 50 years after pregnancy.
Women with preeclampsia or gestational hypertension had a two- to three-fold increased rate of developing high blood pressure, a 70 percent higher rate of type 2 diabetes, and a 30 percent higher rate of high cholesterol, than women who had normal blood pressure in pregnancy. These cardiovascular disease risk factors also developed at younger ages and sooner after pregnancy in women with preeclampsia or gestational hypertension in pregnancy. The relative risk of developing high blood pressure was strongest within five years after first birth, and the increased risk persisted for several decades. Women with high blood pressure during more than one pregnancy were even more likely to develop high blood pressure, diabetes, and high cholesterol. The relationships observed between preeclampsia and gestational hypertension with cardiovascular disease risk factors were not explained by shared risk factors such as pre-pregnancy body mass index, smoking, or family history.
“As recommended by the American Heart Association, doctors should obtain a detailed history of pregnancy complications from their patients and screen women who had high blood pressure in pregnancy at regular intervals after pregnancy for cardiovascular disease risk factors,” Stuart said.
This research was funded by the National Institutes of Health grant UM1 CA176726; supported by awards from the American Heart Association (12PRE9110014, 13GRNT17070022); Training Grant T32HL098048 from the National Heart, Lung, and Blood Institute; Training Grant T32HD060454 from the National Institute of Child Health and Human Development; and the Ruth L. Kirschstein National Research Service Award (NHLBI F31 HL131222).
Brigham and Women's Hospital (BWH) is a 793-bed nonprofit teaching affiliate of Harvard Medical School and a founding member of Partners HealthCare. BWH has more than 4.2 million annual patient visits and nearly 46,000 inpatient stays, is the largest birthing center in Massachusetts and employs nearly 16,000 people. The Brigham’s medical preeminence dates back to 1832, and today that rich history in clinical care is coupled with its national leadership in patient care, quality improvement and patient safety initiatives, and its dedication to research, innovation, community engagement and educating and training the next generation of health care professionals. Through investigation and discovery conducted at its Brigham Research Institute (BRI), BWH is an international leader in basic, clinical and translational research on human diseases, more than 3,000 researchers, including physician-investigators and renowned biomedical scientists and faculty supported by nearly $666 million in funding. For the last 25 years, BWH ranked second in research funding from the National Institutes of Health (NIH) among independent hospitals. BWH is also home to major landmark epidemiologic population studies, including the Nurses' and Physicians' Health Studies and the Women's Health Initiative as well as the TIMI Study Group, one of the premier cardiovascular clinical trials groups. For more information, resources and to follow us on social media, please visit BWH’s online newsroom.