What are the NICE (National Institute for Health and Care Excellence) guidelines for managing gestational hypertension (GHTN) in pregnant women?

NICE Guidelines for Gestational Hypertension

For gestational hypertension, initiate antihypertensive treatment at BP ≥140/90 mmHg using methyldopa, labetalol, or long-acting nifedipine, targeting systolic BP 110-140 mmHg and diastolic BP 85-90 mmHg. 1, 2

Blood Pressure Thresholds for Treatment

• Start pharmacological treatment when BP reaches ≥140/90 mmHg in women with gestational hypertension to prevent progression to severe hypertension and reduce maternal complications 3, 1, 2
• The CHIPS trial demonstrated that tight BP control (targeting diastolic 85 mmHg) reduces severe hypertension development and associated maternal complications compared to less tight control 3
• BP ≥160/110 mmHg constitutes a hypertensive emergency requiring immediate treatment within 15 minutes in a monitored setting to prevent maternal stroke 1, 2, 4

First-Line Antihypertensive Medications

• Methyldopa, labetalol, or long-acting nifedipine are equally acceptable first-line agents for non-severe gestational hypertension 3, 1, 2, 5
• Methyldopa has the longest safety track record with 7.5-year infant follow-up data, though use caution in women at risk for postpartum depression 3, 1
• Labetalol can be administered intravenously (20 mg bolus, then 40-80 mg every 10 minutes, maximum 300 mg) for acute severe hypertension 1, 4
• Metoprolol is an acceptable alternative beta-blocker 3, 2

Target Blood Pressure Range

• Maintain systolic BP 110-140 mmHg and diastolic BP 85-90 mmHg during treatment 1, 2, 5
• Never reduce diastolic BP below 80 mmHg as this impairs uteroplacental perfusion and compromises fetal development 1
• For acute severe hypertension, the immediate goal is to decrease mean BP by 15-25%, targeting systolic 140-150 mmHg and diastolic 90-100 mmHg 5, 4

Non-Pharmacological Management for Mild Hypertension

For BP 140-150/90-99 mmHg without adverse features, consider initial conservative approach:

• Close supervision with BP monitoring at least twice weekly initially, then weekly once stable 1, 5
• Activity limitation with some bed rest in left lateral position 3, 5
• Normal diet without salt restriction (salt restriction may induce low intravascular volume near delivery) 3
• Short-term hospitalization may be required to confirm diagnosis and rule out preeclampsia 3, 5

Monitoring Protocol

Maternal monitoring:

• BP checks at least twice weekly initially, then weekly once stable 1, 5
• Proteinuria assessment at each visit to detect progression to preeclampsia 1, 5
• Baseline laboratory assessment including liver enzymes, creatinine, and platelet count 5

Fetal monitoring:

• Antenatal testing for fetal well-being 5
• Ultrasound for growth assessment 4
• Doppler evaluation if growth restriction suspected 4

Indications for Immediate Hospitalization

• BP ≥160/110 mmHg 1, 2, 5
• Development of preeclampsia features (proteinuria, symptoms) 2, 5
• Neurological signs or symptoms (severe headache, visual disturbances) 2
• Inability to control BP with ≥3 antihypertensive drug classes 2

Medications Absolutely Contraindicated

ACE inhibitors, ARBs, and direct renin inhibitors are strictly contraindicated throughout pregnancy due to severe fetotoxicity, particularly in second and third trimesters 3, 1, 2

If taken inadvertently in first trimester, switch immediately to safe alternatives and arrange close monitoring with fetal ultrasound 3

Delivery Planning

• For stable gestational hypertension, plan delivery at 37 weeks and 0 days 1, 5
• If progression to preeclampsia with severe features occurs, deliver promptly regardless of gestational age after immediate stabilization 1, 5
• Approximately 25% of women with gestational hypertension will progress to preeclampsia, requiring vigilant monitoring 5

Prevention Strategies for High-Risk Women

• Low-dose aspirin 75-100 mg daily at bedtime for women with history of early-onset preeclampsia, starting before 16 weeks gestation and continuing until delivery 3, 2
• Calcium supplementation at least 1 g daily almost halves preeclampsia risk, with greatest effect in high-risk women 3, 2

Postpartum Management

• BP recorded shortly after birth with follow-up at 48-72 hours, 7-14 days, and 6 weeks postpartum 5
• Hypertensive disorders can worsen or initially present after delivery, accounting for up to 44% of pregnancy-related deaths in first six days postpartum 6
• Close monitoring in early postpartum period is critical 5, 6

Long-Term Cardiovascular Risk

• Women with gestational hypertension have significantly increased lifetime cardiovascular risk, with relative risk of ischemic heart disease more than doubled 2
• Annual medical review lifelong is recommended for cardiovascular risk assessment, BP control, and metabolic factor management 3, 2, 5
• Aim to achieve prepregnancy weight by 12 months and limit interpregnancy weight gain through healthy lifestyle 3