Race Differences in Blood Pressure Trajectory After Delivery—A Window Into Opportunities to Decrease Racial Disparities in Maternal Morbidity and Mortality

In a prospective cohort study, Hauspurg et al¹ described blood pressure trajectories during the first 6 weeks post partum among more than 1000 women with hypertensive disorders of pregnancy and assessed differences in these trends by self-reported race. Using blood pressure data obtained through a postdischarge remote blood pressure monitoring program, investigators observed a decline of 6.3 mm Hg per week for systolic blood pressure and 3.4 mm Hg per week for diastolic blood pressure in the first 3 weeks after delivery, with stabilization thereafter. More than 70% of women had stage 1 or 2 hypertension at 6 weeks post partum. With respect to racial differences, non-Hispanic Black women had a slower decline in blood pressure and higher rates of persistent hypertension 6 weeks post partum compared with White women (126 of 185 [68.1%] vs 393 of 764 [51.4%]; P < .001). The incidence of postpartum hospital readmission was also higher among non-Hispanic Black women compared with White women during this time period (36 of 213 [16.9%] vs 76 of 804 [9.5%]; P = .02).

The rate of maternal mortality is higher in the United States than in all other developed countries, and the trajectory is heading in the wrong direction. Hypertension is a leading cause of maternal morbidity and mortality as well as obstetrical readmissions.² Racial disparities in maternal mortality and preeclampsia are well established, with non-Hispanic Black women carrying 3- to 4-fold greater risk of dying from pregnancy-related causes.³ They are also more likely to develop preeclampsia and associated complications, such as cardiac arrest, heart failure, and death.

Historic research examining hypertensive disorders of pregnancy has focused on antenatal prevention and intrapartum management. Delivery was previously considered a cure; however, recent data reveal that a subset of women have persistent hypertension. Contemporary studies have shifted focus to the long-term cardiac sequelae after a pregnancy complicated by preeclampsia, with published literature recently identifying associations between preeclampsia and future risk of cardiovascular disease and stroke.⁴ Our rudimentary understanding of blood pressure trajectories post partum and following hospital discharge has limited the development of best practices for postpartum surveillance, management, and counseling. Due to brief postpartum hospitalizations, often single blood pressure checks 3 to 10 days post partum as recommended by the American College of Obstetricians and Gynecologists,⁵ and poorly attended postpartum visits, longitudinal trends in blood pressure after delivery have been difficult to study. This study¹ sheds valuable light on both short- and long-term hypertension resolution using multiple blood pressure values obtained through their remote monitoring program.

A more sophisticated understanding of factors that confer increased risk of persistent hypertension is critical, as nearly 70% of maternal deaths associated with hypertensive disorders occur post partum, some of which occur after 6 weeks.⁶ From a practical perspective, this study¹ contributes to existing literature by identifying patients who may be at higher risk of postpartum morbidity, thereby providing potential opportunity to target and aggressively treat pregnancy-related hypertension in non-Hispanic Black women after delivery with the goal of mitigating disparities in immediate postpartum outcomes as well as in long-term health. The fitted blood pressure trajectories stratified by race during the first 6 weeks post partum (Figure 2 in Hauspurg et al¹) suggest that non-Hispanic Black women were discharged home with higher systolic and diastolic blood pressures and had similar declines from initial values, raising questions as to whether inpatient treatment may affect postpartum resolution. The fitted blood pressure trajectory for women not on antihypertensive therapy (eFigure 2 in Hauspurg et al¹) also suggests potential benefit. However, the interpretation of these trajectories with respect to blood pressure decline remains overall limited by multiple factors, including the unknown prevalence of chronic hypertension by race, the need for treatment with oral antihypertensive agents, the type of antihypertensive agent used, and duration of treatment after delivery. It may be that particular blood pressure agents (eg, β-blockers vs calcium channel blockers vs diuretics) are more effective in specific populations. As more non-Hispanic Black women were discharged receiving medication (63 of 213 [25.6%] vs 183 of 804 [22.8%]; P = .04),¹ timing of antihypertensive discontinuation may affect their persistent hypertension and may also offer an opportunity for potential practice changes that will improve short- and long-term maternal outcomes.

It is important to note that the etiology underlying the slower resolution of hypertension in non-Hispanic Black women remains unclear, and this phenomenon likely contributes only minimally to known racial disparities in maternal mortality. The clinical significance of a 7 mm Hg systolic and 3 mm Hg diastolic blood pressure difference between non-Hispanic Black and White women is questionable as it relates to maternal morbidity. In light of these modest racial differences, it is plausible that social determinants of health and health care access play a more substantial role in mediating disparities. As Hauspurg et al¹ allude to, the consequences of implicit and explicit biases in health care on maternal outcomes should not and cannot be ignored.

A notable aspect of the study that should be highlighted is the use of their previously tested remote blood pressure monitoring program.⁷ Programs for continued blood pressure monitoring after obstetrical discharge should be implemented into routine practice as standard of care, and hospitals should develop innovative strategies, such as the remote monitoring program described, to meet this need. The study provides additional evidence that telemedicine has a role in hypertension care during the postpartum period, a time filled with barriers to in-person visits; remote monitoring of common postpartum conditions, such as hypertension, depression, and breastfeeding difficulties, may provide an opportunity for early interventions not adequately achieved with poorly attended and timed postpartum visits. These novel clinical approaches also offer the potential to expand research in poorly studied arenas of disparities in care and outcomes.

Postpartum care traditionally entails a single, isolated visit approximately 6 weeks post partum. Pregnancy-related Medicaid coverage ends 60 days after giving birth. Both of these must change if we are to going to move the needle on maternal health outcomes in the United States. The American College of Obstetricians and Gynecologists has called for policies that support an ongoing postpartum care process in its Committee Opinion on optimizing postpartum care,⁵ and many other national public health organizations have endorsed the Helping MOMs Act⁸ to expand postpartum Medicaid coverage. The study by Hauspurg et al¹ provides additional supporting evidence for the need to improve coordinated transitions of care and for the value of Medicaid expansion for 1 year post partum. Given the high percentage of mothers who remain hypertensive at 3 to 6 weeks post partum, allowing mothers to transition from their obstetrical clinician to a primary care physician or cardiologist after the 60-day period may be a critical policy change that could decrease maternal deaths in the first year post partum as well as minimize the long-term cardiovascular morbidity associated with pregnancies affected by hypertensive disorders.

Published: December 22, 2020. doi:10.1001/jamanetworkopen.2020.31122

Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2020 Hirshberg A. JAMA Network Open.

Corresponding Author: Adi Hirshberg, MD, Department of Obstetrics and Gynecology, Maternal Child Health Research Center, University of Pennsylvania Perelman School of Medicine, 3400 Spruce St, Second Floor, Philadelphia, PA 19104 (adi.hirshberg@pennmedicine.upenn.edu).

Conflict of Interest Disclosures: Dr Hirshberg reported codeveloping a postpartum remote blood pressure monitoring program used at Penn Medicine and involvement in a prior partnership between Babyscripts and Penn Medicine to develop a remote monitoring postpartum hypertension module.