hypertension in pregnancy - antihypertensive treatment during the postnatal period, including during breastfeeding (chronic hypertension)

Last edited 08/2019

In women with chronic hypertension who have given birth:

• aim to keep blood pressure lower than 140/90 mmHg
• continue antihypertensive treatment, if required (see section below for choice of antihypertensive during the postnatal period)
• offer a review of antihypertensive treatment 2 weeks after the birth, with their GP or specialist

if a woman has taken methyldopa to treat chronic hypertension during pregnancy, stop within 2 days after the birth and change to an alternative antihypertensive treatment (see below for choice of antihypertensive during the postnatal period)

Offer women who have had gestational hypertension and who remain on antihypertensive treatment, a medical review with their GP or specialist 2 weeks after transfer to community care.

Offer women with chronic hypertension a medical review 6-8 weeks after the birth with their GP or specialist as appropriate.

Antihypertensive treatment during the postnatal period, including during breastfeeding:

Treat women with hypertension in the postnatal period who are not breastfeeding and who are not planning to breastfeed in line with the NICE guideline on hypertension in adults.

• there is very little evidence on the efficacy and safety of antihypertensive agents in postnatal women, so the committee made recommendations based on the NICE guideline on hypertension in adults, with adaptations based on the potential effects of medicines on the baby
  • the committee therefore recommended the use of an angiotensin converting enzyme (ACE) inhibitor as first-line treatment, except in women of African or Caribbean family origin, in whom a calcium-channel blocker would be used first line
    • the choice of second-line medicine was modified from the NICE guideline on hypertension in adults as angiotensin receptor blockers, thiazide and thiazide-like diuretics are not recommended during breastfeeding
    • therefore the committee agreed that betablockers should be used as the second-line antihypertensive agent
    • NICE committee also agreed that the medicines with once-daily administration should be used wherever possible and for this reason the committee recommended enalapril in preference to captopril (which is taken 3 times daily) and atenolol as an alternative to labetalol (which is taken 2 to 4 times daily)
      
      

    • treat women with hypertension in the postnatal period who are not breastfeeding and who are not planning to breastfeed in line with the NICE guideline on hypertension in adults

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.

Explain to women with hypertension who wish to breastfeed that:

• antihypertensive medicines can pass into breast milk
• most antihypertensive medicines taken while breastfeeding only lead to very low levels in breast milk, so the amounts taken in by babies are very small and would be unlikely to have any clinical effect
• most medicines are not tested in pregnant or breastfeeding women, so disclaimers in the manufacturer's information are not because of any specific safety concerns or evidence of harm.
• Make decisions on treatment together with the woman, based on her preferences.

As antihypertensive agents have the potential to transfer into breast milk:

• consider monitoring the blood pressure of babies, especially those born preterm, who have symptoms of low blood pressure for the first few weeks
• when discharged home, advise women to monitor their babies for drowsiness, lethargy, pallor, cold peripheries or poor feeding

Offer enalapril * to treat hypertension in women during the postnatal period, with appropriate monitoring of maternal renal function and maternal serum potassium.

For women of black African or Caribbean family origin with hypertension during the postnatal period, consider antihypertensive treatment with:

• nifedipine (**) or
• amlodipine if the woman has previously used this to successfully control her blood pressure

For women with hypertension in the postnatal period, if blood pressure is not controlled with a single medicine, consider a combination of nifedipine(or amlodipine) and enalapril. If this combination is not tolerated or is ineffective, consider either:

• adding atenolol or labetalol to the combination treatment or
• swapping 1 of the medicines already being used for atenolol or labetalol

When treating women with antihypertensive medication during the postnatal period, use medicines that are taken once daily when possible.

Where possible, avoid using diuretics or angiotensin receptor blockers to treat hypertension in women in the postnatal period who are breastfeeding or expressing milk.

Notes:

• * in 2009, the MHRA issued a drug safety update on ACE inhibitors and angiotensin II receptor antagonists: recommendations on how to use during breastfeeding, and a subsequent clarification was issued in 2014. This clarification states: 'although ACE inhibitors and angiotensin II receptor antagonists are generally not recommended for use by breastfeeding mothers, they are not absolutely contraindicated. Healthcare professionals may prescribe these medicines during breastfeeding if they consider that this treatment is essential for the lactating mother. In mothers who are breastfeeding older infants, the use of captopril, enalapril, or quinapril may be considered if an ACE inhibitor is necessary for the mother. Careful follow-up of the infant for possible signs of hypotension is recommended'
  
  
• at the time of publication (June 2019), some brands of nifedipine were specifically contraindicated during pregnancy by the manufacturer in its summary of product characteristics. Refer to the individual summaries of product characteristics for each preparation of nifedipine for further details

Reference:

• NICE (June 2019). Hypertension in pregnancy: diagnosis and management