HOW ARE CORTICOSTEROIDS USED?

To help prevent these a course of antenatal corticosteroids or ACS may be given. Most research studies show that this treatment is beneficial if it is given between 24 hours and 7 days before the baby is born. We do not know how long the benefit from the treatment lasts. If the baby has not been born 14 days after this treatment and there is still a risk of preterm delivery, there may be a benefit from receiving multiple courses of ACS.  

The risks and benefits of multiple courses of ACS are not clear. We know that a single course of ACS reduces the risk of RDS in babies born before 32 weeks of gestation. Several small studies in humans have found that multiple courses of ACS may reduce the risk of problems for the baby without adverse effects, but the studies were too small to know if the benefits are real. However, because some small studies in animals have shown that ACS can result in decreased growth in the uterus and delay in the development of the nervous system, it is important to be very certain that the benefits of multiple courses of ACS outweigh the risks before this treatment is recommended generally. There are no known benefits or risks for mothers from multiple courses of ACS, other than the discomfort from receiving the injections. Finally, there may be unknown benefits as well as adverse effects for mothers and babies. We need a large well-designed study like this one to clarify if multiple courses of ACS are truly beneficial.