What are the signs of hypertension in pregnancy and how is it managed?

Signs of Hypertension in Pregnancy

Pregnant women should be educated that hypertension in pregnancy is defined as blood pressure ≥140/90 mmHg confirmed on repeated measurements, and they must seek immediate medical attention if they develop severe hypertension (≥160/110 mmHg), which requires treatment within 15 minutes to prevent stroke. 1

Key Blood Pressure Thresholds to Recognize

Diagnostic criteria:

• Hypertension: Systolic BP ≥140 mmHg and/or diastolic BP ≥90 mmHg, confirmed on at least 2 separate occasions 1
• Severe hypertension: Systolic BP ≥160 mmHg and/or diastolic BP ≥110 mmHg, requiring confirmation within 15 minutes 1
• Women should understand that blood pressure normally decreases in early pregnancy, so hypertension developing after 20 weeks is particularly concerning 1

Warning Signs and Symptoms Requiring Immediate Evaluation

Severe features that indicate urgent medical attention:

• Visual disturbances (blurred vision, seeing spots, light sensitivity) 2
• Severe persistent headache that doesn't respond to usual pain relievers 2
• Upper abdominal pain, particularly right upper quadrant or epigastric pain 2
• Sudden swelling of face, hands, or feet (though some swelling is normal in pregnancy) 1
• Shortness of breath or difficulty breathing 1
• Decreased urine output 1

These symptoms may indicate preeclampsia with severe features, which can rapidly progress to life-threatening complications including stroke, seizures (eclampsia), kidney injury, or heart failure 1, 2.

Types of Hypertension in Pregnancy

Women should understand the classification:

• Chronic hypertension: Present before pregnancy or diagnosed before 20 weeks gestation 1
• Gestational hypertension: New hypertension developing after 20 weeks without protein in urine 1, 2
• Preeclampsia: Gestational hypertension with proteinuria (≥0.3 g/day or ≥30 mg/mmol urinary creatinine) 1, 2
• Transient gestational hypertension: Blood pressure elevation detected in clinic that normalizes with repeated readings over several hours, but carries a 40% risk of progressing to true gestational hypertension or preeclampsia 1

Management Approach

Initial management when hypertension is detected:

• Blood pressure should be repeated to confirm true hypertension rather than a single elevated reading 1
• For severe hypertension (≥160/110 mmHg), confirmation should occur within 15 minutes and treatment initiated urgently in a monitored setting 1, 2, 3
• For less severe elevations, repeated readings should be taken over several hours 1

Treatment thresholds:

• Antihypertensive medication is initiated at BP ≥140/90 mmHg for women with gestational hypertension, preeclampsia, or hypertension with organ damage 2, 4
• Target blood pressure is diastolic around 85 mmHg and systolic 110-140 mmHg to balance maternal safety with adequate placental blood flow 1, 2

First-line medications:

• Oral methyldopa, labetalol, or nifedipine are the recommended first-line agents 2
• For severe hypertension requiring urgent treatment: IV labetalol, oral nifedipine, or IV hydralazine 2, 3
• Critical contraindication: ACE inhibitors, ARBs, and direct renin inhibitors are strictly prohibited in pregnancy due to severe fetal toxicity 1, 2, 3

Monitoring and Follow-up

Home monitoring considerations:

• Women may be instructed to monitor blood pressure at home using validated automated devices 1, 5
• Proper technique is essential: appropriate cuff size, correct arm position, no talking during measurement, avoiding caffeine and smoking beforehand 5
• Home blood pressure monitoring has been shown to improve blood pressure control and outcomes across diverse populations 1

Frequency of assessment:

• Women with transient gestational hypertension require careful follow-up given the 40% progression risk 1
• Regular prenatal visits with blood pressure checks at each visit are essential 4
• Screening for proteinuria should occur if BP reaches ≥140/90 mmHg, as approximately 25% of gestational hypertension cases progress to preeclampsia 4

Postpartum Considerations

Critical postpartum period:

• The majority of hypertension-related maternal deaths occur after delivery when blood pressure peaks 1
• Blood pressure should be checked at 6 weeks postpartum, and women with persistent hypertension or proteinuria require specialist referral 3
• Women who experienced hypertensive disorders of pregnancy have increased long-term cardiovascular risk and require annual medical review lifelong 2
• Lifestyle modifications, regular blood pressure monitoring, and control of metabolic factors are recommended to reduce future stroke and hypertension risk 2

Common Pitfalls to Avoid

• Do not delay treatment of severe hypertension, as this increases stroke risk and other complications 3
• Do not dismiss symptoms such as headache or visual changes as "normal pregnancy discomforts"—these may indicate dangerous progression 2
• Do not assume normotensive readings in early pregnancy rule out chronic hypertension, as the physiological blood pressure decrease in the first trimester can mask pre-existing hypertension 1
• Ensure proper blood pressure measurement technique, as inaccurate readings can lead to missed diagnoses or unnecessary treatment 5