Corticosteroids in pregnancy to reduce complications from being born prematurely

Steroids are naturally occurring chemical messengers (hormones) that are essential for life. Corticosteroids are a man-made type of medication that may be offered to you to help your baby if there is a chance that you may give birth early. Steroids are given by an injection into the muscle, usually of your thigh or upper arm. The steroids pass into your blood and then cross the placenta to reach your baby. A single course can consist of two injections, usually over a 24-hour period.

Babies born early, before 37+0 weeks, may have a range of health problems, which tend to be more serious the earlier they are born.

Giving you steroid injections shortly before your baby is born reduces the risk of them having serious complications including:

• Problems with their breathing (respiratory distress syndrome)
• Reduces the chance of your baby dying
• Bleeding into their brain
• Bowel inflammation
• Developmental delay.

If steroids are given within seven days of your baby being born prematurely there is a reduced chance of them dying around the time of birth.

Babies born between 24+0 and 33+6 weeks benefit most from steroids and you will be offered steroids if your baby is likely to be born early between this time

Steroids can be considered if your pregnancy is between 34+0 weeks and 35+6 weeks and if there is an increased chance that your baby will be born early. You will have the chance to discuss the risks and benefits of steroids with your healthcare professional to make the best decision for you and your baby. Reasons to give you steroids include:

• if you are in suspected or confirmed premature labour
• if your waters break early, even if you are not having contractions (see the RCOG patient information When your waters break prematurely).
• if it may benefit you or your baby for them to be born early. This may be because your baby is not growing well or because you have developed a problem in your pregnancy such as severe pre-eclampsia (see RCOG patient information on Pre-eclampsia).

If you are likely to give birth between 35 weeks and 37weeks, or are having a planned caesarean birth before 39 weeks, you should have an individualised discussion with your healthcare professional about the risks and benefits of steroids for your baby. There is less evidence that steroids are helpful after 35 weeks and less evidence on the benefits of steroids for babies born by caesarean section between 37 and 39 weeks

The benefits of steroids in twin and triplet pregnancies are less certain, but it is still recommended that you should be offered steroids if you are likely to give birth early.

Steroids may be given if your baby is expected to be born between 22 and 24 weeks, but this will require an individualised discussion with your healthcare team about the risks to your baby of being born so prematurely.

Steroids are of most benefit if the last dose is given to you between 24 hours and 1 week before the birth of your baby. There may still be some benefit even if your baby is born within 24 hours of the first dose. The benefits of steroids are likely to be significantly reduced if your baby is born more than 7 days after the treatment. Therefore, it is important to try to give steroids at the right time.

A single course of steroids is safe for you and your baby. You may experience some minor side effects such as pain at the injection site, nausea, flushing and a rise in blood sugar if you are diabetic. See the RCOG patient information on Gestational Diabetes.

If you have diabetes, you will need increased monitoring of your blood sugar levels while you have the steroids and may need to be admitted to hospital to be offered additional insulin treatment.

Treatment with steroids between 22 and 35 weeks pregnant is likely to be safe and beneficial for your baby. No long-term harm has been shown although there have been no large studies.

For babies born near their due date by caesarean section it is still uncertain if steroids can help to reduce breathing problems or if steroids reduce the overall possibility a baby is admitted to the neonatal unit.

Some research suggests that there may be an impact on mental wellbeing later in life for babies born at full term (after 37 weeks) who were given steroids between 22 and 37 weeks. There are still uncertainties and less information is available on longer term effects of steroids in babies, particularly those born near their due date.

If you are given steroids and are more than 35 weeks pregnant there is a chance that your baby may have low blood sugar levels after they are born. Low blood sugar can be harmful for babies if it is not treated and can mean your baby needs to be admitted to the neonatal unit. Your baby will be monitored for this and offered treatment if needed.

If you have had a course of steroids and you do not give birth in the next 7 days then a second course might have some beneficial effects on your baby’s breathing if they are still expected to be born prematurely. Evidence to support this benefit is limited and there is also evidence that a repeat course of steroids may mean your baby is smaller than they should be when they are born. Your healthcare professional will advise you of the risks and benefits of a repeat course of steroids depending on your individual situation.

If you are unlikely to give birth in 7 days, you should not receive steroids. Even if you are at higher risk of giving birth early you won’t be given steroids unless you are likely to give birth in the next 7 days.