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.