Hypertensive disorders of pregnancy in the United States increased from approximately 500 cases per 10,000 deliveries to 1,021 cases per 10,000 deliveries from 1993 to 2016-2017, and remain a leading cause of maternal morbidity and mortality, wrote Task Force Chair Michael J. Barry, MD, of Massachusetts General Hospital, Boston, and colleagues in the final recommendation statement published in JAMA.
The USPSTF commissioned a systematic review to assess the risks and benefits of hypertensive screening for asymptomatic pregnant women. The resulting grade B recommendation indicates that screening for hypertensive disorders in pregnancy using blood pressure measurements yields a substantial net benefit.
The recommendation applies to “all pregnant women and pregnant persons of all genders without a known diagnosis of a hypertensive disorder of pregnancy or chronic hypertension,” the authors said.
The recommendation calls for the use of blood pressure measurements to evaluate hypertensive disorders, with measurements taken at each prenatal visit. A positive result for new-onset hypertension was defined as systolic blood pressure of 140 mm Hg or diastolic blood pressure 90 mm Hg in the absence of chronic hypertension, based on two measurements at least 4 hours apart. Regular review of blood pressure can help identify and manage potentially fatal conditions.
However, screening alone is insufficient to improve inequities in health outcomes associated with hypertensive disorders of pregnancy, the authors emphasized. Data from previous studies have shown that Black patients are at increased risk for hypertensive disorders of pregnancy and severe complications, and that Black and Hispanic patients have twice the risk of stroke with hypertensive disorders of pregnancy as White patients.
In the evidence report that supported the recommendation, Jillian T. Henderson, PhD, of Kaiser Permanente in Portland, Ore., and colleagues reviewed six studies including 10,165 individuals. The studies (five clinical trials and one nonrandomized study) compared changes in prenatal screening with usual care.
Overall, the review yielded no evidence that any other screening strategies were more useful than routine blood pressure measurement to identify hypertensive disorders of pregnancy in asymptomatic women.
The findings cited to support the recommendation were limited by several factors, including the lack of power to detect pregnancy health outcomes and potential harms of different screening programs, and the lack of power to evaluate outcomes for American Indian, Alaska Native, or Black individuals, who have disproportionately high rates of hypertensive disorders of pregnancy, the authors said.
More research is needed to identify which screening approaches may lead to improved disease detection and better health outcomes, but the results of the review support the grade B recommendation for hypertensive screening of all pregnant women, they concluded.
Early identification makes a difference
The new recommendation is important because it can help all moms and babies to be healthier, said Wanda Nicholson, MD, vice chair of the task force, in an interview.
Dr. Wanda Nicholson
“We are recommending that all pregnant persons have a blood pressure check at every visit throughout pregnancy,” said Dr. Nicholson, an ob.gyn. by training who also serves as professor of prevention and community health at George Washington University in Washington. “We know that there is a maternal health crisis in this country, and we know that hypertensive disorders of pregnancy are one of the key factors related to that,” she said.
Unfortunately, barriers to routine screening for hypertensive disorders of pregnancy persist, said Dr. Nicholson. The incidence of hypertensive disorders of pregnancy is higher in many of the same populations who also have challenges in accessing regular prenatal care, notably those who are Black, Native American, or Alaska Native, she noted.
The new recommendation also serves as an opportunity to call attention to the health care disparities for these populations, not only during pregnancy, but in general, she emphasized.
In clinical practice, the definition of hypertensive disorders of pregnancy involves three different diagnoses – gestational hypertension, preeclampsia, and eclampsia – that can be seen as points on a continuum, said Dr. Nicholson. The sooner patients are identified with hypertensive disorders of pregnancy, the sooner intervention and treatment can begin, she said. To that end, she added the clinical pearl of using a properly sized blood pressure cuff to obtain an accurate reading and avoid missed diagnoses.
The task force also outlined several key areas for additional research, said Dr. Nicholson. First, more research is needed on alternative screening strategies, such as at-home blood pressure monitoring for patients, as well as teleheath visits. Second, more studies are needed to address the disparities in prenatal care and include more diverse populations in clinical research. Third, future studies need to consider social determinants of health and other factors that might impact maternal health outcomes. “These steps will help achieve the larger goal of healthier mothers and babies,” Dr. Nicholson said.