Optimizing the Approach to Adverse Pregnancy Outcomes and Long-Term Cardiovascular Risk: Missed Opportunities and Future Directions

Maternal mortality in the United States, a leading cause of death for women aged 20-34,¹ is a national embarrassment and demands aggressive strategies to address the growing rate and inequities of maternal health in our country. In 2020, the US maternal mortality rate was 3-times higher than any other high-income country, with stark disparities among White and Black birthing people. Underscoring US disparities, Black individuals have a 3-4 fold higher maternal mortality and a 50% higher risk of severe maternal morbidity as compared with White women². Cardiovascular disease and cardiovascular-related events account for over a third of these deaths, predominantly in the postpartum period³. A staggering 80% of deaths have been deemed preventable by Maternal Mortality Review Committees, with provider knowledge and assessment as leading domains for potential intervention. A major risk factor, or at least a means of identifying higher-risk patients, is adverse pregnancy outcomes (APOs), a composite of fetal growth restriction, hypertensive disorders of pregnancy and preeclampsia, placental abruption, stillbirth, and preterm delivery.

Many of these APOs result from failure of the extravillous trophoblasts to sufficiently invade and remodel the maternal spiral arteries leading to reduced blood flow in the intervillous space, hypoxia, and a systemic maternal inflammatory response⁴. This systemic inflammatory response results in endothelial damage and, ultimately, increased cardiovascular risk. As is well-summarized within this Scientific Statement, preeclampsia specifically portends a 71% increased risk for CVD-related mortality, a 2.5-fold increased risk for coronary artery disease, a 4-fold increased risk of heart failure, and a 2-fold increased risk for metabolic syndrome or diabetes over their lifetime when compared with normal cohorts. Earlier onset (< 34 weeks) and more severe disease carry the highest overall lifetime risk^5,6. Given that APOs affect up to 30% of the pregnant population, there is opportunity for both short- and long-term CVD risk modification⁷.

In this issue of Circulation, Opportunities in the postpartum period to reduce cardiovascular disease risk following adverse pregnancy outcomes represents a critically important and timely AHA Scientific Statement. It summarizes the current evidence on cardiovascular risk modification for women with a history of APOs and reviews both strategies and the need for future research to better care for such patients with the goal of improving their long-term cardiovascular health. The authors highlight current evidence on CVD risk reduction in the interpregnancy period, including the promotion of breastfeeding, effective long-acting contraception, and optimizing blood pressure through home surveillance. This Statement is an important complement to a recent joint Statement from the American College of Obstetrics and Gynecology (ACOG) and the American Heart Association (AHA) highlighting the need for a multidisciplinary strategy to prevent CVD-related morbidity in pregnant women at risk for CVD. As pointed out in that Scientific Statement, there are no evidence-based strategies on when, how, and who should be screened in order to reduce CVD risk⁶. Thus, the focus on those experiencing APOs for lifestyle and behavioural modifications, including diet, exercise, and glucose management begins to address this gap. Importantly, while APOs are clearly a ‘seminal opportunity' to identify higher-risk individuals, those with pre-existing CVD and no APOs also represent a high-risk group for which these recommendations could also apply. This highlights an additional important research direction for the field, which would be to create multi-variable risk models, including social determinants of health and the contribution of systemic and interpersonal discrimination, to identify pregnant people at increased risk for post-partum hypertension, diabetes, and CVD so that the entire population of higher-risk pregnant people can be proactively engaged in CV risk screening and treatment.

At the core of this challenge in recognizing and treating cardiovascular risk in pregnant people is the transition of care from puerperium to long-term care. US healthcare is highly fractured and challenges in transitions in cardiovascular care from the inpatient to the outpatient setting, including heart failure and myocardial infarction, became a national priority after the introduction of penalties by Medicare for higher-than-predicted readmission rates. Yet, despite this focus on developing better transitions in care, few successful strategies have been identified. In the setting of pregnancy, the ‘transition of care' is from specialized obstetric care to general practitioners. The concept of the ‘fourth trimester' of pregnancy is a terrific means for communicating this transitional period and could potentially become the foundation of national educational campaigns to increase awareness of this transition for patients and providers alike. While this Statement highlights ‘challenges and solutions' at the patient-, practice-, and ecological-level, implementation and sustainability of these ‘solutions' is unknown and requires much additional research.

Some strategies to better leverage the fourth trimester as a critical opportunity to improve cardiovascular health are outside the locus of control of providers and mandate policy changes to implement. For example, significant barriers to timely and accessible postpartum care stem from the lack of insurance coverage after delivery. Medicaid is the primary health insurance for over 45% of pregnant people, yet several states have not extended Medicaid coverage beyond 60 days after delivery, precluding poorer patients from affording follow-up and management of their cardiovascular health. Even those with employee-based or Affordable Health Care Act insurance coverage may not be able to receive effective contraception as part of their insurance benefits, leaving them vulnerable to shortened interval pregnancy spacing and even higher risk for recurrent APOs. Addressing these ecological challenges requires working with State and National legislative bodies.

Although policy and insurance barriers to care are not immediately addressable, this Statement highlights a number of strategies that can be addressed today. For example, home blood pressure monitoring is a possible solution for reducing racial and rural disparities. Multiple studies have shown that it is feasible, effective, and increases self-efficacy, even in those with low health literacy and lower socioeconomic status⁸. Developing better strategies for implementing home blood pressure monitoring is important for three critical reasons: 1) Up to 74% of marginalized birthing people are lost to care in the year following birth (with the highest rates for those with APOs) and having a window of access through remote monitoring could reduce the loss of these patients to care, 2) APO-related CVD events can occur as early as one year postpartum and, without intervention, can lead to life-long morbidity and 3) promoting the management of this high-risk group of individuals in settings outside of traditional primary care (i.e. by obstetricians or cardiologists) dampens the burden on an already critical shortage of primary care providers, particularly in rural areas where both maternal and CVD-related morbidities are highest^5,9. Defining implementation strategies for monitoring home blood pressure testing and referring those with hypertension to longitudinal management are clear priorities for US healthcare. Further insight into how best to engage patients who, by definition, are busy caring for their newborns to take advantage of additional telehealth support also necessitates further research. Yet, even if randomized clinical trials and implementation scientists can address these challenges, obtaining the financial support from health systems to invest in such efforts may prove challenging as the reimbursement from payers may be much less than the costs of such programs.

Establishing evidence-based postpartum guidelines for the management of women with APOs (and all who are at higher risk for CVD) is a very timely contribution from this Statement as it provides strategies to harness evolving investments from both the public and private sectors in maternal health. On December 7, 2021, President Biden and Vice President Harris joined ACOG and AHA in acknowledging that maternal mortality is a major public health crisis demanding immediate attention¹⁰. They introduced the Maternal Care and Black Maternal Health Momnibus Acts to expand access, diversify the perinatal workforce, and improve data collection and maternal health risk monitoring. Current efforts to improve maternal health continue to rely on expert opinion or retrospective data collection, which lack clinically nuanced data to better risk-stratify outcomes. Further, there are no detailed plans in either bill to identify the contribution of patient-centered risk factors, such as health status and perceived discrimination. Leveraging the concepts articulated in this Statement and investing in future research on both better risk identification than APOs alone (although this is a very good starting place) and implementation science to systematically improve the transitions of care for high-risk patients to receive support in achieving Life's Essential 8, is a critical step to improving the care, equity and outcomes of pregnant people and to addressing the crisis of adverse maternal mortality in the US.