What is the management of hypertension in a pregnant woman?

Management of Hypertension in Pregnancy: Sample Exam Questions and Answers

Question 1: First-Line Antihypertensive Agents

A 28-year-old woman at 24 weeks gestation presents with blood pressure of 152/98 mmHg confirmed on repeat measurement. She has no proteinuria. Which medication should be initiated?

Answer: Methyldopa, labetalol, or nifedipine should be initiated as first-line therapy for this patient with gestational hypertension. 1, 2

Rationale:

• The 2017 ACC/AHA guidelines establish that women with hypertension in pregnancy should be transitioned to methyldopa, nifedipine, and/or labetalol, as these are the only recommended agents 1
• Treatment should be initiated at BP ≥140/90 mmHg in women with gestational hypertension, preeclampsia, or hypertension with organ damage 2
• Methyldopa has the longest safety record with 30-year follow-up data showing no adverse effects on children at 7.5 years of age 1
• Labetalol has comparable efficacy to methyldopa and can be given orally (100 mg twice daily, up to 2400 mg/day) 1, 3
• Nifedipine (extended-release formulation) is safe and effective, though short-acting nifedipine should be avoided 1, 4

Critical Contraindications:

• ACE inhibitors, ARBs, and direct renin inhibitors are absolutely contraindicated due to severe fetotoxicity, particularly in second and third trimesters 1, 4
• Atenolol should be used with caution as it is associated with fetal growth retardation related to duration of treatment 1

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Question 2: Severe Hypertension Emergency Management

A 32-year-old woman at 34 weeks gestation presents to labor and delivery with BP 168/114 mmHg, severe headache, and visual disturbances. Repeat BP 15 minutes later is 172/116 mmHg. What is the immediate management?

Answer: This patient requires immediate IV labetalol administration with a target BP of 140-150/90-100 mmHg within 15-60 minutes, along with magnesium sulfate for seizure prophylaxis. 2, 4

Immediate Actions:

• Severe hypertension (BP ≥160/110 mmHg) is a medical emergency requiring hospitalization and treatment within 15 minutes to prevent maternal stroke 1, 2, 4
• IV labetalol is the first-line agent for acute severe hypertension, given as bolus administration that can be repeated until BP is controlled 4
• Alternative agents include oral nifedipine or IV hydralazine, though hydralazine is no longer preferred due to more perinatal adverse effects 1
• The goal is to reduce mean BP by 15-25%, targeting SBP 140-150 mmHg and DBP 90-100 mmHg—not normotension 4

Seizure Prophylaxis:

• Magnesium sulfate should be administered for prevention of eclampsia in severe preeclampsia 4
• Critical warning: Magnesium sulfate should NOT be given concomitantly with calcium channel blockers due to risk of severe hypotension from synergistic effects 4

Monitoring Requirements:

• Continuous maternal monitoring for early warning criteria including SBP <90 or >160 mmHg, DBP >100 mmHg, heart rate <50 or >130 bpm, oxygen saturation <95%, oliguria, altered mental status, and non-remitting headache 4
• Continuous fetal monitoring if gestational age ≥24 weeks 5

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Question 3: Medication Selection in Early Pregnancy

A 30-year-old woman with chronic hypertension on lisinopril 20 mg daily presents for preconception counseling. What medication changes are necessary?

Answer: Lisinopril must be discontinued immediately and replaced with methyldopa, labetalol, or nifedipine before conception or as soon as pregnancy is confirmed. 1

Medication Transition:

• ACE inhibitors cause severe fetotoxicity and are strictly contraindicated throughout pregnancy 1, 4
• If ACE inhibitors are taken inadvertently during first trimester, immediate switching to safe alternatives with close monitoring including fetal ultrasound is required 1
• The three safe first-line options are methyldopa (longest safety data), labetalol (comparable efficacy), and nifedipine extended-release 1, 2

Preconception Counseling:

• Women with chronic hypertension require prepregnancy evaluation and close monitoring during and after pregnancy 6
• Target BP during pregnancy should maintain diastolic around 85 mmHg and systolic 110-140 mmHg 2
• Diastolic BP should not fall below 80 mmHg as this may impair uteroplacental perfusion 5

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Question 4: Treatment Thresholds

A 26-year-old primigravida at 28 weeks gestation has BP readings of 146/94 mmHg and 148/96 mmHg at a routine prenatal visit. She is asymptomatic with no proteinuria. Should antihypertensive therapy be initiated?

Answer: Yes, antihypertensive medication should be initiated at BP ≥140/90 mmHg in this patient with gestational hypertension. 2, 7

Treatment Thresholds:

• Current European guidelines recommend initiating treatment at BP ≥150/95 mmHg in general, but at ≥140/90 mmHg in women with gestational hypertension, preeclampsia, or hypertension with organ damage 2, 8, 7
• The 2017 ACC/AHA guidelines support treatment at ≥140/90 mmHg to prevent progression to severe hypertension 1
• Treatment reduces the risk of progression to severe hypertension by 50% compared with placebo 1

Non-Pharmacologic Management:

• For BP 140-149/90-99 mmHg without other risk factors, close supervision and limitation of activities may be considered initially 1
• A normal diet without salt restriction is advised—salt restriction may induce low intravascular volume 1, 2
• Left lateral decubitus positioning can help relieve aortocaval compression 5

Monitoring:

• Screen for proteinuria when BP reaches ≥140/90 mmHg, as approximately 25% of gestational hypertension cases progress to preeclampsia 2
• Regular prenatal visits with BP checks at each visit are essential 2

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Question 5: Postpartum Management

A 29-year-old woman delivered 3 days ago after being treated for preeclampsia. Her BP is now 158/102 mmHg. How should this be managed?

Answer: Continue or initiate antihypertensive therapy with methyldopa, labetalol, or nifedipine, targeting BP <140/90 mmHg, and schedule follow-up at 6 weeks postpartum. 2, 4

Postpartum Considerations:

• Hypertension may persist or worsen in the immediate postpartum period, requiring continued treatment 4
• Monitor for postpartum complications including stroke and eclampsia, which can occur up to 6 weeks postpartum 4
• Gestational hypertension should resolve within 42 days (6 weeks) postpartum; persistence suggests pre-existing chronic hypertension 1, 4

Medication Safety in Breastfeeding:

• Methyldopa appears in breast milk; caution should be exercised 9
• Labetalol is excreted in minimal amounts (approximately 0.004% of maternal dose) in human milk 3
• Nifedipine is excreted in human milk; nursing mothers are advised not to breastfeed when taking the drug 10

Long-Term Follow-Up:

• Women with hypertensive disorders of pregnancy have increased long-term cardiovascular risk and require annual medical review lifelong 2, 6, 7
• BP should be checked at 6 weeks postpartum, and women with persistent hypertension or proteinuria require specialist referral 2
• Obstetric history should become part of cardiovascular risk assessment in women 7

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Question 6: Pulmonary Edema Complication

A 33-year-old woman at 36 weeks gestation with severe preeclampsia develops acute shortness of breath and oxygen saturation of 88% on room air. Chest X-ray shows pulmonary edema. What is the antihypertensive of choice?

Answer: IV nitroglycerin is the drug of choice for preeclampsia complicated by pulmonary edema, starting at 5 mcg/min and titrating up to maximum 100 mcg/min. 1, 4

Specific Management:

• In preeclampsia associated with pulmonary oedema, nitroglycerin (glycerol trinitrate) is preferred over other agents 1, 4
• Dosing: Start at 5 mcg/min IV infusion, increase every 3-5 minutes to maximum 100 mcg/min 4
• Avoid diuretics for pulmonary edema in preeclampsia, as this is a common pitfall 4

Alternative Agents to Avoid:

• Sodium nitroprusside remains an option for hypertensive crises but carries risk of fetal cyanide poisoning with prolonged administration 1
• IV hydralazine should no longer be considered first-line due to association with more perinatal adverse effects 1

Definitive Management:

• Delivery is the definitive treatment for severe preeclampsia; immediate delivery is indicated for severe heart failure and/or fetal distress 4