Addressing the Postpartum Care Gap in Hypertensive Disorders
The transition from pregnancy to postpartum care, often referred to as the “fourth trimester,” represents a critical yet frequently overlooked window in maternal health. While prenatal care is highly structured, the six weeks following childbirth often lack the same intensity of monitoring, despite the high risk of cardiovascular complications. Hypertensive disorders of pregnancy (HDP)-including preeclampsia and gestational hypertension-affect up to 10 percent of pregnancies in the United States and serve as significant predictors for long-term cardiovascular morbidity.
Clinicians also note that cardiovascular risks can extend well beyond the traditional six‑week visit, with some experts now describing a postpartum period that evolves over acute, subacute, and delayed phases lasting up to six months after birth. This underscores how poorly conventional follow-up schedules align with the biology of recovery.
The current clinical standard for preventing recurrent HDP relies primarily on the administration of low-dose aspirin in high‑risk patients. However, this intervention must be initiated early in a subsequent pregnancy to be effective. This creates a systemic vulnerability for mothers who face barriers to early prenatal care or those with unplanned pregnancies, and it limits what health systems can do once a complicated pregnancy has already occurred.
To address this gap, a five-year, $3.2 million project funded by the National Heart, Lung, and Blood Institute is shifting the focus of intervention to the interval between pregnancies. Led by Dr. Samantha Parker Kelleher and Dr. Christina Yarrington, the study aims to quantify how postpartum hypertension influences the risk of recurrent HDP and identify strategies to lower these rates, which currently range from 15 to 45 percent in the U.S. The work could ultimately inform how national guidelines are written and how insurers, including Medicaid programs, structure benefits around postpartum care.
We know that early prenatal care does improve maternal health outcomes, but many mothers may be at a disadvantage for those early interventions if they experience barriers to care, or don’t realize they’re pregnant until later. With this study, we’re trying to shift interventions to an even earlier stage-before subsequent pregnancies-to get mothers into a good position to have healthy, uncomplicated pregnancies.
Dr. Parker Kelleher, principal investigator of the project
Systemic Risks and Population Impact
Hypertensive disorders during pregnancy are not distributed evenly across the population. Systemic healthcare disparities contribute to higher incidence and severity rates among marginalized communities, where access to continuous primary care is often limited. Those inequities sit against a national backdrop of rising maternal mortality and morbidity, which federal agencies now classify as an urgent public health crisis.
For hospital systems and policymakers, HDP functions as both a clinical and structural warning signal: a marker of future cardiovascular disease in the individual patient, and a proxy for where the health system is failing to deliver consistent, high‑quality care.
| Risk Factor/Indicator | Impact and Clinical Significance |
|---|---|
| Population Prevalence | Up to 10% of all U.S. pregnancies; 15-45% recurrence rate in subsequent pregnancies. |
| Demographic Disparity | Disproportionate impact on Black and Hispanic pregnant people, reflecting broader inequities in access, racism in care delivery, and social determinants of health. |
| Postpartum Transition | Up to 50% of women with HDP develop hypertension in the first six weeks post-birth, a period when many have limited contact with clinicians. |
| Long-term Morbidity | Increased risk of stroke, chronic hypertension, and cardiovascular disease, creating a continuum from obstetric complication to adult cardiac care. |
| Recurrence Risk | At least 70% of mothers with multiple children and prior HDP face elevated heart disease risks, amplifying the impact on families and community health systems over time. |
At Boston Medical Center (BMC), a primary safety-net institution serving diverse and underserved populations, the prevalence of these disorders is stark and has direct implications for how limited resources are allocated.
Black and Hispanic pregnant people are disproportionately affected by hypertensive disorders of pregnancy, and about 30 percent of BMC patients experience these disorders before or during pregnancy.
For public officials and payers, these figures sharpen ongoing debates about how long postpartum coverage should last and how aggressively systems should invest in community-based monitoring and follow-up.
Remote Monitoring and Regulatory Thresholds
The integration of digital health tools is central to mitigating the risks of preeclampsia and related complications. BMC has implemented a home blood pressure monitoring program utilizing cloud-connected cuffs that transmit near-real time data to clinicians via cellular technology. This infrastructure allows for remote medication adjustments and urgent in-person evaluations, reducing the likelihood of hospital readmissions and acute events such as seizures or strokes.
At the same time, national guidance is evolving. In the United States, professional societies and federal agencies increasingly align clinical recommendations with the blood pressure definitions used in broader cardiovascular care. The American College of Obstetricians and Gynecologists, whose practice bulletins are frequently referenced by regulators and payers, is a key conduit through which emerging evidence from programs like BMC’s can translate into standard-of-care expectations for hospitals and health plans.
Post-pandemic, many barriers that prevent patients from accessing regular prenatal and postpartum care remain, as does the risk of hypertensive disorders of pregnancy,” says study investigator Dr. Erica Holland, an obstetrician-gynecologist at BMC and assistant professor of obstetrics and gynecology at BU’s Chobanian & Avedisian School of Medicine. “Our blood pressure monitoring program enables clinicians to assess and manage elevated blood pressure remotely, and to facilitate urgent in-person evaluation. This timely treatment aims at preventing readmission, as well as the life-altering complications of preeclampsia, such as seizure and stroke.
A primary objective of the research is to refine clinical guidelines regarding the threshold for prescribing antihypertensive medications during the postpartum period-an area where individual clinician discretion often fills gaps in formal rules.
- Previous Threshold: Medications were typically considered at 150/100 mmHg, reflecting older risk tolerances for short-term elevations.
- Current Definition: Hypertension is now defined as two or more readings of at least 140/90 mmHg, bringing obstetric thresholds closer to general adult cardiovascular standards.
- Project Goal: Assess the health impacts of lowering the medication threshold to determine if earlier intervention reduces the risk of recurrent HDP and long-term cardiovascular events.
Findings from this work could feed into future updates to federal quality measures and maternal safety bundles, shaping how hospitals are evaluated and reimbursed for postpartum care.
Biological and Behavioral Mitigators
Beyond pharmacological intervention, the study is examining the role of breastfeeding and primary care engagement in reducing cardiovascular risk. Research suggests that breastfeeding may provide an immediate and long-term protective effect on maternal heart health, in part through its influence on blood pressure, lipid profiles, and weight trajectories.
Breastfeeding has been shown to improve multiple maternal health outcomes, including reduced risk of cardiovascular disease later in life, but also in the immediate postpartum period,” says study investigator Dr. Katherine Standish, family medicine physician, founder and codirector of BMC’s Breastfeeding and Lactation Medicine Center, and assistant professor of family medicine at the Chobanian & Avedisian School of Medicine. “As soon as one month after initiating breastfeeding, improved cardiovascular indicators have been seen, though like many breastfeeding-related outcomes, risk reduction is greater the longer the length of time one breastfeeds.
However, the study notes that acute illness during delivery often creates barriers to breastfeeding initiation, especially for patients recovering from severe preeclampsia or emergency cesarean sections. Those are the same patients most likely to benefit from closer cardiovascular surveillance, making early lactation support a potentially powerful-but often underfunded-lever for maternal health policy.
By analyzing electronic health records from approximately 3,500 patients between 2016 and 2025, the research team aims to identify the optimal timing and support systems needed to maximize these benefits, including how quickly patients are linked to primary care after delivery and whether health insurance coverage remains stable through the first postpartum year.
By learning more about how breastfeeding might reduce the risk of future hypertensive diseases, our study can help us identify mothers who would most benefit from breastfeeding, and the optimal timing to help mothers breastfeed, both for their own and for their baby’s health,” Dr. Standish says.
Taken together, the work at BMC points toward a reframing of the “fourth trimester” as a regulated, resourced phase of care rather than an informal afterthought. As federal and state authorities, including the Centers for Medicare & Medicaid Services, continue to extend postpartum coverage and refine quality metrics, evidence from safety-net institutions will be critical in determining whether maternal cardiovascular risk is meaningfully reduced-or simply more precisely documented.