Using corticosteroids during pregnancy

Question

I recently learned that steroids are sometimes given to mothers in preterm labor.

For example:

If a baby is at risk of being born too early, giving the mother steroids before the birth can help her unborn baby's lungs to develop more quickly. This reduces the risk of the newborn having serious complications or dying

Pregnancy and birth: Before preterm birth: What do steroids do?

However, steroids are also the drug of choice during pregnancy for certain disease, for example for asthma, or in inflammatory diseases because they fight inflammation and NSAIDs should not be taken during pregnancy, if it can be avoided.

For example:

For example, steroid tablets may be recommended if you're pregnant and have severe asthma, because the risk to your baby from uncontrolled asthma is higher than from the medication.

Corticosteroids - Who can use them

Is premature development of the lungs, the desired effect when giving steroids for preterm labor, one of these risks? In other words, when giving steroids to a pregnant woman, does the effect on the fetus's lungs pose any risks?

Answer 1

The steroid given to help mature a baby's lungs is either dexamethasone or bethamethasone. These are given by injection and readily cross the placenta.

The steroids to treat asthma are usually things like beclomethasone which are usually given via inhalation or orally, are taken at different doses, and are metabolized by the placenta differently.

As a result, they have different physiologic effects on the developing fetus and of the mother carrying the fetus. There are risks both to the mother and the developing fetus of taking the medications, but also of not taking the medications. The specifics depend on the particular setting, so for a more detailed/nuanced discussion, you should speak to your doctor.