Pregnancy complications may predict cardiovascular risk
By Adrienne D. Zertuche, MD, MPH, FACOG
After surviving the nearly year-long prenatal plight with morning sickness, back pain, heartburn and swelling – and then successfully navigating the early postpartum weeks of vaginal bleeding, raw nipples, urinary incontinence and sleeplessness – most women cannot wait to mark their pregnancy as a distant memory. But there is a growing body of evidence that women and their physicians should do just the opposite.
Pregnancy is increasingly being described as “a window to a woman’s future health,” because complications that occur during pregnancy offer a glimpse into health problems that may arise later in life. The incredible changes that occur as a woman’s body accommodates a growing fetus constitute “nature’s stress test.” If problems occur during this physiologic challenge, they may portend a higher lifelong risk of diabetes, hypertension and cardiovascular disease (including heart attack and stroke).
Experts surmise that three common pregnancy complications may in fact be the earliest clinical signs of latent chronic disease, including cardiovascular disease.
- Gestational diabetes affects approximately 6% of pregnancies, and while some women can manage their glucose levels by adapting their diet and exercise regimen, many require the assistance of medications, including insulin. Regardless of their disease severity, however, women with gestational diabetes are seven times more likely to go on to develop type 2 diabetes than women without gestational diabetes. They are also twice as likely to develop cardiovascular disease.
- Hypertensive disorders of pregnancy (including gestational hypertension, preeclampsia and eclampsia) complicate nearly 10% of pregnancies. Women with elevated blood pressure in pregnancy have a fivefold increased risk of developing chronic hypertension later in life, and they are also twice as likely to develop cardiovascular disease. Not surprisingly, the relationship between the severity of preeclampsia/eclampsia and later disease is graded, and the risk of cardiovascular disease is highest for women with recurrent preeclampsia and early-onset preeclampsia requiring preterm delivery.
- Preterm delivery, low birthweight and placental abruption have variable underlying pathogeneses, but they all predict an increased maternal risk of cardiovascular disease. For instance, preterm delivery (<37 weeks) occurs in approximately 12% of pregnancies, and it may occur spontaneously or be medically induced. Women with preeclamptic-related preterm deliveries are at a sevenfold increased risk of cardiovascular disease, but even normotensive mothers that deliver early (most of which do so spontaneously) have a threefold increased risk. Neonatal birthweight also predicts maternal lifespan. A mother’s cardiovascular-related mortality increases by 25% for each standard deviation toward a lower neonatal birthweight, and women who deliver <2500g (~5.5 lbs.) infants are twice as likely to die from this disease as women who deliver >3500g (~7.7 lbs.) infants.
These pregnancy-related conditions, which affect at least 20% of all women, share many features with cardiovascular disease, but the exact mechanism that explains their role as a window to future health is not yet well understood. Interestingly, studies suggest that half of the pregnancy-associated elevated risk of future cardiovascular disease can be explained by factors that were present prior to pregnancy.
Certainly, endothelial dysfunction (including hyperlipidemia and atherosclerosis) occurs in both cardiovascular disease and in these obstetric conditions. However, some experts hypothesize that the stress experienced by a woman’s cardiovascular system during pregnancy triggers a biologic remodeling that would not otherwise have occurred, even in the setting of pre-existing risk factors.
Regardless of the mechanism underlying nature’s obstetric stress test, it undoubtedly provides a woman and her physician with a valuable glimpse into her future. Patient education is critical to a woman understanding how her obstetric history impacts her cardiovascular risk, but the primary responsibility in arranging appropriate ongoing care falls on the healthcare team. Unfortunately, surveys demonstrate that most physicians (including obstetrician/gynecologists and cardiologists) are wholly unaware of the association, and standardized screening and referral guidelines are lacking.
A comprehensive approach to minimization of cardiovascular risk begins immediately postpartum. For most women, weight gain is a natural part of pregnancy; however, excessive gestational weight gain and postpartum weight retention are risk factors for obesity, which is a key factor in cardiovascular risk progression. Encouraging mothers to breastfeed may help their weight loss journey and may even have a distinct cardioprotective effect. Then, at postpartum and subsequent routine gynecological visits, obstetrician/gynecologists should clearly counsel women on their pregnancy course, recommend relevant lifestyle modifications and create an appropriate follow-up plan, including screening and referrals for specialty care when indicated.
Accurate documentation of obstetric history in the patient’s medical record is also critical, as is communication with other members of the woman’s healthcare team. Until there is more widespread recognition and acceptance of pregnancy as a window to future health, deliberate and even prescriptive messaging may be required.
It should also be noted that women of color are disproportionately affected by pregnancy complications; not surprisingly, they also bear a higher burden of cardiovascular disease. In a healthcare system that has historically marginalized racial and ethnic minorities, physicians must make an extra effort to recognize individual biases and systemic barriers that impact efforts to improve the health of these and all women.
Patient and physician education about the role of pregnancy complications in prediction of lifelong cardiovascular risk is especially critical in Georgia, where our maternal, infant and chronic illness outcomes leave much to be desired:
- The preterm delivery rate in Georgia is 11.4%, which earned our state a D- on the 2021 March of Dimes Report Card.
- Only one state has a higher maternal mortality rate than Georgia. The leading cause of pregnancy-related death in Georgia is cardiomyopathy (accounting for 25%); cardiovascular and coronary conditions also account for 6%.
- Georgia has the sixth highest rate of cardiovascular disease in the United States, and more than 1 in 5 women have some form of cardiovascular disease.
In an effort to address these poor pregnancy and chronic disease outcomes and their socioeconomic disparities, patients and physicians have recently advocated at Atlanta’s Gold Dome for postpartum extension of comprehensive Medicaid coverage. While it is only the first of many steps toward full integration of pregnancy care with lifelong cardiovascular risk reduction efforts, the anticipated impact of extending coverage from six weeks to (hopefully) one year postpartum cannot be overstated.
Heart attack, stroke and other cardiovascular diseases claim the lives of more than 500,000 American women each year, which is more lives than the next 14 causes of death combined, including all forms of cancer. These diseases cause different symptoms and signs in women than they do in men, and as a result, they are more likely to go undetected until they are severe.
As a community, we must recognize the impact of cardiovascular disease in women and capitalize on the ability of the pregnancy stress test to provide a window to their future health. Greater emphasis on frequent patient/physician discussion of obstetric history may provide for risk mitigation, early detection and improved outcomes for women of all walks of life.
Georgia Department of Community Health. “Cardiovascular Disease.” Accessed online 2022 Jan at www/dch.georgia.gov.
Georgia Maternal Mortality Review Committee. “Reducing Maternal Mortality in Georgia – Case Review Update 2013.” 2017 Nov. Accessed online 2022 Jan at www.gaobgyn.org.
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Interpregnancy care. Obstetric Care Consensus No. 8. American College of Obstetricians and Gynecologists. Obstet Gynecol 2019;133:e51–72.
March of Dimes. ”2021 March of Dimes Report Card (Georgia).” Accessed online 2022 Jan at www.marchofdimes.org.
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Dr. Zertuche provides comprehensive obstetric and gynecologic care for women of all ages at Piedmont Women’s Healthcare in Atlanta. She holds leadership roles within the American College of Obstetrics & Gynecology, Georgia Obstetrical & Gynecological Society, Piedmont AtlantaHospital, and Emory University School of MedicineAlumni Board, and she frequents the state and federal Capitol buildings as a women’s health advocate.