If there’s a chance your baby may be born early, your team may offer you a short course of corticosteroids. These are well-established, widely-used medicines that help prepare your baby’s lungs and reduce serious complications if they are born preterm.
This page explains what they are, who is offered them, and what to expect.
Babies born before about 35 weeks of pregnancy have lungs that aren’t fully developed. A short course of corticosteroids given to you before birth crosses the placenta and helps your baby’s lungs mature more quickly.
Corticosteroids also lessen the chance of your baby having other serious complications after an early birth, including:
For babies born early, these effects can be life-saving.
You may be advised to have corticosteroids if there is an increased chance that your baby will be born before 35 weeks of pregnancy. This includes:
Your obstetric team will explain why corticosteroids are being suggested in your individual situation, and give you the chance to ask questions.
Corticosteroids are given as two injections into the muscle of your thigh or buttock, 12 to 24 hours apart. The full benefit is reached around 24 hours after the second dose, and lasts for around 7 days.
The medication is well-tolerated. Most women have no side effects other than mild discomfort at the injection site. Some women notice transient effects on blood glucose levels — particularly if you have diabetes, your team will monitor and adjust your insulin accordingly.
Antenatal corticosteroids are one of the most studied and most effective treatments in obstetrics. They have been shown to substantially reduce neonatal death, respiratory problems, brain bleeds and infection in babies born preterm.
A single course is usually enough. In some cases — for example, if the risk of preterm birth recurs more than 7 days later — a repeat dose may be considered. Your team will discuss this with you.
Corticosteroids are still recommended in this situation, as your baby may still be born before full term. You will also usually be offered antibiotics and close monitoring.
Even a partial course gives some benefit. Whenever there is time, the steroids are given.
Most women feel no different. Diabetic women may need closer blood glucose monitoring. Very rarely, there are side effects — your team will discuss these with you and answer any concerns.
In specific clinical situations — for example, a severe infection — the timing and balance of risks may need to be considered. Your obstetric team will weigh this carefully for you.
