You’re working the night shift in a rural critical access hospital in the Midwest when a 36-year-old, 31-week primigravida patient with no known prior medical history presents with a mild headache. Initial vitals show a blood pressure (BP) of 170/115 mm Hg, which remains elevated 15 minutes later. You follow the recommended emergency department (ED) lab workup for hypertensive disorders of pregnancy, including urine protein/creatinine ratio, serum creatinine, platelet count, complete blood count, and renal liver function tests.

Fetal monitoring reveals normal fetal heart rate assessment. The physical exam is unrevealing, with no focal neurologic deficits or abdominal tenderness. A urine test reveals protein/creatinine ratio of less than 0.3; lab tests show no signs of end-organ dysfunction. Aiming to start treatment within the goal of the first 30 to 60 minutes of confirmed severe hypertension, you initiate an oral antihypertensive with immediate release oral nifedipine 10 mg and acetaminophen for her mild headache while the nurse works on intravenous (IV) access.

Once an IV is established, you first administer labetalol 20 mg IV because antihypertensive treatment is the priority, followed by magnesium sulfate 6 g IV over 20 minutes. Her headache abates after the acetaminophen. You advise the nurse to recheck the BP every 10 minutes with a target BP of 130-150/ 80-100 mm Hg and a plan to increase labetalol doses based on rechecks.

You call the nearest hospital, but because they don’t have a neonatal intensive care unit (NICU), they advise you to call another one. You speak with the OB/GYN team at that hospital, and they recommend steroids for fetal lung maturation because the pregnancy is less than 34 weeks gestation. After a few more rounds of IV labetalol, BP is stabilized, and the patient, now diagnosed with severe gestational hypertension, is flown via air ambulance to the nearest hospital with a NICU.

Acute Hypertension in Pregnancy

Hypertensive disorders of pregnancy are the second leading cause of maternal morbidity and mortality and can also result in fetal complications. Maternal complications of this medical emergency include stroke, eclampsia, and HELLP—hemolysis, elevated liver enzymes, low platelet count—syndrome. Timely treatment can reduce these risks.

The consideration of delivery in severe gestational hypertension must balance risks for maternal and fetal complications, as immediate delivery can reduce maternal complications but can increase the risk for neonatal respiratory distress syndrome, particularly when performed before 37 weeks of gestation. Importantly, these conditions can appear up to six weeks postpartum, which is why it is essential for ED screening to include the question for reproductive age women: Are you pregnant or have you been pregnant in the last six weeks?

Patients with gestational hypertension are at increased risk for preeclampsia, HELLP syndrome, preterm birth, small-for-gestational-age infants, and placental abruption. Risk factors include obesity, use of assisted reproductive technology, prior preeclampsia, and multifetal gestation. Older maternal age and obesity contribute to increasing incidence. Close monitoring is essential to detect progression to severe hypertension or preeclampsia, particularly in those diagnosed before 34 weeks, those with systolic BP greater than 135 mm Hg, or those with a history of miscarriages.

Case Definitions^1,2

Chronic hypertension: Hypertension (140/90 mm Hg or greater) presents before pregnancy or is diagnosed before the 20th week of gestation.

Superimposed preeclampsia: A patient with chronic hypertension who has passed after the 20th week of gestation and develops new-onset proteinuria (protein/creatinine 0.3 or greater; urine dipstick 2+ or greater) or other signs of end-organ dysfunction such as:

Renal insufficiency: Creatinine levels greater than 1.1 mg/dL or a doubling of baseline creatinine

BP worsening: Typically, 160/110 mm Hg or greater, despite previously controlled chronic hypertension

Thrombocytopenia: Platelet count less than 100×10⁹/L

Impaired liver function: Elevated AST/ALT [aspartate aminotransferase/alanine aminotransferase] twice the upper limit of normal, often associated with right upper quadrant or epigastric pain

Pulmonary edema: New-onset fluid accumulation in the lungs

Neurological symptoms: Persistent severe headache, vision changes, or altered mental status

Gestational hypertension: New-onset hypertension (140/90 mm Hg or greater) after 20 weeks of pregnancy in a previously normotensive patient. It differs from preeclampsia because it does not include proteinuria OR signs of end-organ dysfunction.

Severe gestational hypertension: BP at severe levels (160/110 mm Hg or greater), which remains elevated despite initial management efforts. Although the condition may lead to preeclampsia, it differs because it occurs without proteinuria or systemic findings of end-organ dysfunction.

Preeclampsia: Gestational hypertension AND either proteinuria OR systemic signs. Severe preeclampsia includes severe hypertension (systolic BP160 mm Hg or greater or diastolic BP 110 mm Hg or greater), significant proteinuria, and evidence of organ dysfunction). It can occur at any time after 20 weeks but is more common after 34 weeks.

HELLP syndrome: Serum aminotransferase levels 70 U/L or greater, platelet count less than 100×10⁹/L, and LDH less than 600 U/L. HELLP affects less than 1 percent of pregnancies but has a seven percent to 70 percent perinatal mortality rate and a one percent to 24 percent maternal mortality rate.3 Symptoms are nonspecific, including nausea, vomiting, and abdominal pain.

Management^4–7

American College of Obstetricians and Gynecologists (ACOG) guide to Obstetric Emergencies in Nonobstetric Settings has issued the following guidance based on the Acute Hypertension in Pregnancy and Postpartum Algorithm regarding immediate treatment for severe hypertension (SBP greater than160 mm Hg, DBP greater than110 mmHg). Recommended antihypertensive drugs include labetalol, nifedipine, and hydralazine. According to ACOG guidelines, once BP is controlled (less than 160/110), it should be monitored every 10 minutes for an hour, every 15 minutes for the next hour, and every 30 minutes for the following hour.

Labetalol: An initial dose of 20 mg IV over two minutes is to be repeated at 10-minute intervals as needed, increasing to 40 mg and 80 mg on subsequent pushes, after which a switching agent is recommended. Avoid parenteral labetalol with active asthma, heart disease, or congestive heart failure; use with caution with a history of asthma.

Hydralazine: 5 mg to 10 mg IV over two minutes, to be repeated at 20-minute intervals as needed, increasing to 10 mg on a subsequent dose, after which switching agent is recommended. Maximum cumulative IV-administered doses should not exceed 25 mg in 24 hours. It may increase the risk for maternal hypotension.

Oral nifedipine: 10 mg capsules. Capsules should be administered orally, not punctured, or otherwise administered sublingually.

Antihypertensive treatment is the priority, followed by magnesium treatment for seizure prevention. The loading dose is four grams to six grams IV over 20 to 30 minutes, followed by a maintenance dose of one to two grams per hour. Contraindications to magnesium include myasthenia gravis, and caution should be used with renal failure or pulmonary edema. Magnesium can be administered as 10 g of a 50 percent solution IM (five grams in each buttock) without access.

Drugs to Avoid^8–10

When treating pregnant patients for hypertension, avoid atenolol and propranolol because of reports of fetal growth restriction, angiotensin-converting enzyme (ACE) inhibitors, which may cause major congenital malformations, angiotensin II receptor blockers (ARBs) because of interference with fetal renal hemodynamics, and mineralocorticoid receptor antagonists (spironolactone, eplerenone, amiloride) and nitroprusside because of limited safety data available. Additionally, diuretics are not typically administered to pregnant patients.

Postpartum Risks

Hypertensive disorders of pregnancy significantly increase postpartum risks for preeclampsia and stroke. Patients should be educated on key symptoms to watch for, such as severe headache, visual disturbances, swelling, shortness of breath, chest pain, vomiting, or seizures. Early intervention is critical to preventing severe complications, and some may require prolonged antihypertensive treatment.

Conclusion

Hypertensive disorders in pregnancy, particularly severe gestational hypertension and preeclampsia, pose significant risks to both mother and fetus. As emergent obstetric resources across the United States become more limited, the ED plays a critical role in improving maternal and fetal outcomes for both pregnant and recently pregnant patients in early detection, close monitoring, and timely treatment.

Dr. Solnick is an assistant professor in emergency medicine and research faculty at the Icahn School of Medicine at Mount Sinai in New York City.

Ms. Allison Warren is completing her final year as an honors undergraduate student at Yeshiva University majoring in biology and minoring in chemistry.

References

1. Cífková R. Hypertension in pregnancy: A diagnostic and therapeutic overview. High Blood Press Cardiovasc Prev. 2023;30(4):289-303.
2. The American College of Obstetricians and Gynecologists. Clinical Guidance for the Integration of the Findings of the Chronic Hypertension and Pregnancy (CHAP) Study. Reaffirmed March 2024. Accessed November 30, 2024.
3. Mihu D, Costin N, Mihu CM, et al. HELLP syndrome a multisystemic disorder. J Gastrointestin Liver Dis. 2007;16(4):419-424.
4. The American College of Obstetricians and Gynecologists. ACOG Committee opinion no. 767: emergent therapy for acute-onset, severe hypertension during pregnancy and the postpartum period. Obstet Gynecol. 2019;133(2):e174-e180.
5. Garovic VD, Dechend R, Easterling T, et al. Hypertension in pregnancy: Diagnosis, blood pressure goals, and pharmacotherapy: A scientific statement from the American heart association. Hypertension. 2022;79(2):e21-e41.
6. The American College of Obstetricians and Gynecologists and Safe Motherhood Initiative. Checklist: Hypertensive Emergency [Internet]. Revised January 2019. Accessed January 5, 2025.
7. The American College of Obstetricians and Gynecologists. Obstetric Emergencies in Nonobstetric Settings: Acute Hypertension in Pregnancy and Postpartum Algorithm. Accessed November 30, 2024.
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9. Cooper WO, Hernandez-Diaz S, Arbogast PG, et al. Major congenital malformations after first-trimester exposure to ACE inhibitors. N Engl J Med. 2006;354(23):2443-2451.
10. Sibai BM. Diagnosis and management of gestational hypertension and preeclampsia. Obstet Gynecol. 2003;102(1):181-192.