CardioNerds (Amit Goyal and Daniel Ambinder), Cardio-OB series co-chair and University of Texas Southwestern Cardiology Fellow, Dr. Sonia Shah, and episode lead and Columbia University Cardiology Fellow Dr. Ersilia DeFilippis discuss hypertensive disorders of pregnancy (HDP) with Dr. Jennifer Lewey from the University of Pennsylvania.
In this episode, we cover chronic hypertension, gestational hypertension, and pre-eclampsia—all of which encompass HDP and complicate approximately 5-10% of all pregnancies. We also review risk factors for HDP, diagnostic criteria, peripartum and postpartum management, and much more! Be sure to tune in to hear Dr. Lewey discuss the future impact of HDP on cardiovascular disease for women later in life and strategies that can help improve care.
Finally Dr. DeFilippis shares her perspectives from her ACC.org FIT Section article titled “Shattering the Glass” including strategies to shattering the glass and tackling imposter syndrome in improving the representation of women in medicine.
- To make a diagnosis of HDP, blood pressure should be measured on at least 2 occasions at least 4 hours apart.
- Hypertension diagnosed before 20 weeks gestation is considered chronic hypertension whereas hypertension after 20 weeks is categorized as gestational hypertension.
- Always check for warning signs for pre-eclampsia!
- One of the key treatments for pre-eclampsia is delivery but pre-eclampsia can occur still in the postpartum period.
- Aspirin use in pregnancy during second and third trimesters can reduce the risk of pre-eclampsia among women at risk.
“Ideally a lot of these conditions come down to prevention and addressing potential cardio-obstetrics issues before they reach the cardio-obstetrics specialist.”
“Blood pressure can continue to be elevated even after delivery.”
“Pregnancy complications not only increase cardiovascular risk in the middle age population but also in the postmenopausal population.”
“Women feel so relieved when they know that their care team is dedicated to taking care of women with cardiovascular disease when they are pregnant.”
- Why should CardionNrds learn and know about hypertensive disorders of pregnancy?
Hypertensive disorders of pregnancy (HDP) complicate about 5-10% of all pregnancies. HDP is a term that encompasses chronic hypertension, gestational hypertension, pre-eclampsia, and pre-eclampsia superimposed on chronic hypertension. Women with history of HDP are at increased risk for stroke, ischemic heart disease, and cardiovascular death later in life. It is important to include obstetric history as part of our assessment of cardiovascular risk.
This obstetric history should include the number of pregnancies, history of gestational diabetes, gestational hypertension, history of pre-eclampsia as well as history of pre-term birth.
Following delivery, these women need close monitoring for development of chronic hypertension as well as primary prevention of cardiovascular disease.
2. How is gestational hypertension distinguished from chronic hypertension?
The key factor in distinguishing gestational hypertension from chronic hypertension is the timing of diagnosis. Before 20 weeks gestation, elevated blood pressure (defined as a reading > 140/90 on two occasions at least 4 hours apart) is considered chronic hypertension. After 20 weeks gestation, elevated blood pressures signify a pregnancy-induced process, namely gestational hypertension or pre-eclampsia if blood pressure elevation is severe enough or there is evidence of end-organ damage.
Blood pressure is often lower in the 1st and 2nd trimesters due to lower systemic vascular resistance. We think the process of gestational hypertension and pre-eclampsia result from how spiral arteries implant in the uterus. There are a whole host of local factors that lead to an increase in blood pressure later on in pregnancy.
3. What are warning signs of pre-eclampsia?
Pre-eclampsia is diagnosed in the setting of high blood pressure, usually after 20 weeks, in the setting of proteinuria or end-organ dysfunction. End-organ dysfunction most commonly includes thrombocytopenia, transaminitis, right upper quadrant pain, headaches, pulmonary edema, and symptoms and signs that are not explained by other causes. Notably, blood pressure readings greater than > 160/110 mm Hg are sufficient for the diagnosis in the absence of other findings.
4. What are risk factors for pre-eclampsia or pre-eclampsia superimposed on chronic hypertension?
Risk factors for pre-eclampsia include a personal or family history of pre-eclampsia in prior pregnancies, chronic hypertension, older age, multiple gestation, obesity, and Black race.
5. When do we start treatment for hypertension during pregnancy?
For women who are newly diagnosed with hypertension during pregnancy, the threshold to begin treatment is 160 mm systolic and 110 mm diastolic. The caveat to this is for women with known cardiovascular disease or other comorbidities, a lower blood pressure goal should be targeted closer to 120-130 mm Hg systolic over 80 mm diastolic. Typically, a higher blood pressure is tolerated in order to avoid uteroplacental hypoperfusion which can impact the growth of the baby.
The CHIPS randomized trial was published in the NEJM in 2015 and compared less tight control (targeting diastolic blood pressure of 100 mm Hg) or tight control (targeting diastolic blood pressure of 85 mm Hg). Although tight control decreased the rate of severe maternal HTN, there was no significant difference in the risk of pregnancy loss or overall maternal complications.
- How can we modify risk in women with hypertension during pregnancy?
Low dose aspirin use (81 mg daily) in pregnancy during second and third trimesters can reduce the risk of pre-eclampsia among women at risk. The USPTF recommends the use of aspirin as preventative medication after 12 weeks of gestation in women at high risk for pre-eclampsia (Grade B). Risk factors that qualify someone as high risk include history of pre-eclampsia, multifetal gestation, chronic hypertension, type 1 or 2 diabetes, renal disease, and/or autoimmune disease. ACOG also recommends aspirin prophylaxis initiated between 12 and 28 weeks of gestation, optimally before 16 weeks and continued daily until delivery.
7. What is the best approach to anti-hypertensive medication use in pregnancy?
First line agents used during pregnancy for treatment of hypertension include labetalol and nifedipine. Hydralazine is a second-line agent that may be used. Although methyldopa classically appears on board exams, it is less effective and has side effects including depression and fatigue.
For women with a history of hypertension prior to pregnancy that is well-controlled on agents such as amlodipine or hydrochlorothiazide, these can be continued since limited evidence suggests they are safe although there is just less available evidence.
For women on angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, or mineralocorticoid antagonists, these must be stopped given their teratogenic effects.
This table from a recent JACC review by Halpern et al summarizes nicely safety of antihypertensive medications in pregnancy and during breastfeeding.
8. How do we treat pre-eclampsia?
Treatment of pre-eclampsia depends on severity and gestational age. Management is primarily two-fold: 1) using intravenous medications such as labetalol and hydralazine to lower the blood pressure; 2) magnesium sulfate for seizure prophlaxis. Delivery may help resolve the symptoms of pre-eclampsia and may be considered following 37 weeks gestational age.
Wang Y-X, Arvizu M, Rich-Edwards JW, et al. Hypertensive disorders of pregnancy and subsequent risk of premature mortality. J Am Coll Cardiol. 2021;77(10):1302-1312. doi.org/10.1016/j.jacc.2021.01.018.
Dr. Jennifer Lewey is an Assistant Professor at the University of Pennsylvania, Director of Penn Women’s Cardiovascular Health Program, and Co-Director of the Pregnancy and Heart Disease Program.
Ersilia DeFilippis is a third-year general cardiology fellow at Columbia University Irving Medical Center in New York City. She will be beginning her fellowship in advanced heart failure and transplant cardiology next academic year at Columbia. Her research and clinical interest are in sex differences in advanced heart failure management and outcomes, racial disparities in heart failure outcomes, and cardio-obstetrics.