Offer pregnant women with chronic hypertension advice on:

• weight management
• exercise
• healthy eating
• lowering the amount of salt in their diet

Provide this advice in line with Management of hypertension guidance

Antihypertensive treatments in pregnancy

Aim for a target blood pressure of 135/85 mmHg

Continue with existing antihypertensive treatment if safe in pregnancy, or switch to an alternative treatment (see below).

Offer antihypertensive treatment to pregnant women who have chronic hypertension and who are not already on treatment if they have blood pressure of 140/90 mmHg or higher.

In women with other markers of potentially severe disease, treatment can be considered at lower degrees of hypertension.

Consider the following treatment options:

Base the choice on any pre-existing treatment, side-effect profiles, risks (including foetal effects) and the woman's preference. NICE recommends the following:

Labetalol

• Consider labetalol to treat chronic hypertension in pregnant women
• Should only be used during the first trimester of pregnancy if the potential benefits are likely to outweigh the possible risk to the foetus
• Refer to BUMPS factsheet to consider risks and benefits of labetalol in pregnancy
• See 2.4 Beta-adrenoceptor blocking drugs

Nifedipine (modified release)

• Consider nifedipine for pregnant women in whom labetalol is not suitable
• May inhibit labour; manufacturer advises avoid before week 20, but risk to foetus should be balanced against risk of uncontrolled maternal hypertension
• Refer to BUMPS factsheet to consider risks and benefits of nifedipine in pregnancy
• See 2.6.2 Calcium-channel blockers

Methyldopa

• Consider methyldopa if both labetalol and nifedipine are not suitable
• Refer to BUMPS factsheet to consider risks and benefits of methyldopa in pregnancy
• Women should stop methyldopa within two days after the birth and change to a different drug if required.
• See 2.5.2 Centrally acting antihypertensive drugs

For further information on the use of these medicines in pregnancy, refer to the UK Teratology Information Service

Pre-eclampsia

Offer pregnant women with chronic hypertension aspirin 75-150mg once daily (with evening meal) from 12 weeks until birth to prevent pre-eclampsia (unlicensed indication). Local specialists recommend 150mg once daily. See below for risk factors for pre-eclampsia.

Women with at least one high risk factor OR two moderate risk factors for pre-eclampsia should be prescribed aspirin 75-150mg once daily (with evening meal), from 12 weeks until birth (unlicensed indication). Local specialists recommend 150mg once daily.

High risk factors

• Hypertensive disease during a previous pregnancy
• Chronic kidney disease
• Autoimmune disease (such as systemic lupus erythematosus (SLE) or antiphospholipid syndrome)
• Type 1 or type 2 diabetes
• Chronic hypertension

Moderate risk factors

• Nulliparous
• Being 40 years of age or older
• More than 10 years since a previous pregnancy
• Family history of pre-eclampsia
• BMI 35kg/m² or more at booking
• Multiple pregnancy
• Sickle cell disease

Stop methyldopa within two days after the birth and change to a different drug if required. Continue other antenatal antihypertensives if required, and measure blood pressure daily for the first two days after birth, then at least once between day 3 and 5. Aim to keep blood pressure below 140/90 mmHg.

Women should be reviewed by their GP or specialist as appropriate, 2 weeks after birth and then again 6–8 weeks after the birth or as per discharge information.

Reduce antihypertensive treatment if blood pressure falls below 130/80mmHg.

Advise women with hypertension who wish to breastfeed that their treatment can be adapted to accommodate breastfeeding, and that the need to take antihypertensive medication does not prevent them from breastfeeding.

Additional information on the use of medicines in lactation is available from the UK Drugs in Lactation Advisory Service (UKDILAS)

For women who are not breastfeeding, and who require ongoing antihypertensive treatment, refer to management of hypertension

For breastfeeding women who received methyldopa during their pregnancy, or require postnatal commencement of antihypertensive consider:

Enalapril

• Monitor maternal renal function and maternal serum potassium

For women of black African or Caribbean family origin

Nifedipine (modified release)

OR

Amlodipine

• If the woman has previously used this to successfully control her blood pressure.

Alternatives if not controlled with a single medicine

Combination of:

Nifedipine (modified release) plus Enalapril

OR

Amlodipine plus Enalapril

If this combination is not tolerated or is ineffective, consider:

Adding Atenolol or Labetalol to the combination treatment

OR

Swapping one of the medicines already being used for Atenolol or Labetalol

See sections 2.4 Beta-adrenoceptor blocking drugs, 2.5.5 Drugs affecting the renin-angiotensin system, and 2.6.2 Calcium-channel blockers

Advise women who have had a hypertensive disorder of pregnancy that the overall risk of recurrence in future pregnancies is approximately 1 in 5

Any hypertension in previous or current pregnancy

Prevalence of hypertensive disorder in a future pregnancy:

• Any hypertension: Approximately 21% (1 in 5 women)
• Pre-eclampsia: Approximately 14% (1 in 7 women)
• Gestational hypertension: Approximately 9% (1 in 11 women)
• Chronic hypertension: N/A

Pre-eclampsia in previous or current pregnancy

Advise women who have had pre-eclampsia:

• to achieve and keep a BMI within the healthy range before their next pregnancy (18.5–24.9 kg/m²)
• that the likelihood of recurrence increases with an inter-pregnancy interval greater than 10 years

Prevalence of hypertensive disorder in a future pregnancy:

• Any hypertension: Approximately 20% (1 in 5 women)
• Pre-eclampsia: Up to approximately 16% (1 in 6 women)
  • If birth was at 28–34 weeks approximately 33% (1 in 3 women)
  • If birth was at 34–37 weeks: approximately 23% (1 in 4 women)
• Gestational hypertension: Between approximately 6 and 12% (up to 1 in 8 women)
• Chronic hypertension: Approximately 2% (up to 1 in 50 women)

Gestational hypertension in previous or current pregnancy

Prevalence of hypertensive disorder in a future pregnancy:

• Any hypertension: Approximately 22% (1 in 5 women)
• Pre-eclampsia: Approximately 7% (1 in 14 women)
• Gestational hypertension: Between approximately 11 and 15% (up to 1 in 7 women)
• Chronic hypertension: Approximately 3% (up to 1 in 34 women)

Advise women who have had a hypertensive disorder of pregnancy that this is associated with an increased risk of hypertension and cardiovascular disease in later life

Risks described are overall estimates, summarised from risk ratios, odds ratios and hazard ratios. Increased risk is compared to the background risk in women who did not have hypertensive disorders during pregnancy.

Any hypertension in previous or current pregnancy

Risk of future cardiovascular disease:

• Major adverse cardiovascular event: Risk increased (up to approximately 2 times)
• Cardiovascular mortality: Risk increased (up to approximately 2 times)
• Stroke: Risk increased (up to approximately 1.5 times)
• Hypertension: Risk increased (approximately 2 to 4 times)

Pre-eclampsia in previous or current pregnancy

Risk of future cardiovascular disease:

• Major adverse cardiovascular event: Risk increased (approximately 1.5 to 3 times)
• Cardiovascular mortality: Risk increased (approximately 2 times)
• Stroke: Risk increased (approximately 2 to 3 times)
• Hypertension: Risk increased (approximately 2 to 5 times)
• End-stage kidney disease: If no proteinuria or hypertension at 8 weeks postnatal, absolute risk is low. No follow up required

Gestational hypertension in previous or current pregnancy

Risk of future cardiovascular disease:

• Major adverse cardiovascular event: Risk increased (approximately 1.5 to 3 times)
• Cardiovascular mortality: no data
• Stroke: Risk may be increased
• Hypertension: Risk increased (approximately 2 to 4 times)

Chronic hypertension in previous or current pregnancy

Risk of future cardiovascular disease:

• Major adverse cardiovascular event: Risk increased (approximately 1.7 times)
• Cardiovascular mortality: no data
• Stroke: Risk increased (approximately 1.8 times)
• Hypertension: N/A