Nifedipine for premature labour

Key points about nifedipine for premature labour

  • Nifedipine may be given to stop or delay the contractions if you're in premature labour and it's more than 5 weeks before your due date. 
  • Find out how nifedipine is given and possible side effects.
Woman in premature labour
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Nifedipine is commonly used to treat high blood pressure and heart problems. For pregnant people who start to have cramps or contractions too early in pregnancy (between 24 and 34 completed weeks gestation) nifedipine may be used to slow down and stop your contractions. Nifedipine helps to reduce muscle contractions by blocking calcium moving into the muscle cells in your womb (uterus). Depending on how many weeks pregnant you are, there are different risks for your pēpi/baby if they are born prematurely. Read more about premature labour and birth

Delaying your labour can allow more time for you to be given medicines to help your baby while they're still in your uterus.

  • Steroid injections: These may be recommended if you are between 24 and 34 weeks pregnant and your pēpi/ baby may be born prematurely. Steroids are given as 2 injections, 24 hours apart, to help prepare your baby's lungs. If you've been given steroids, your baby is far less likely to have breathing problems (respiratory distress syndrome) and other complications.
  • Magnesium infusion: Magnesium sulfate may be given to protect your baby's brain and reduce their risk of having problems (eg, cerebral palsy) if they're born too early. Magnesium is given as a slow injection into your vein (called an intravenous infusion). It would be recommended if you are 24 to 30 weeks pregnant. 

Delaying your labour may also allow time for you to move to a specialist hospital if necessary. It's much safer to transfer a baby inside a mum than in an incubator.

Note: Nifedipine is not given if you have an infection that's causing your preterm labour, or if you have heavy vaginal bleeding.

For preterm labour, nifedipine slow release 20 mg tablets and fast acting 5 mg capsules are used.

  • Initially nifedipine is given as ‘fast acting’ capsules every 15 minutes for an hour, then followed by ‘slow acting’ tablet(s) for up to 48 hours. The dose is adjusted according to your response.
  • You will need to stay in hospital for close observation during this time.

Nifedipine for premature labour is used for a short time (48 hours or less).

Possible side effects include headaches, flushing in the face and palpitations (fast heart rate). Some people may get a drop in blood pressure, so your blood pressure and heart rate will be monitored closely. Your baby’s heartbeat will also be monitored.

Less common side effects include:

  • constipation
  • dizziness
  • nausea (feeling sick)
  • fatigue
  • swelling of your hands and feet
  • liver function may be affected (very rarely).


  1. Premature labour(external link) Patient Info, UK, 2020

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Credits: Healthify editorial team. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Teresa Bag, Women’s Health Clinical Pharmacist (Pre-specialist), Counties Manukau;
Angela Lambie, Pharmacist, Auckland

Last reviewed: