How Steroids Reduce Preterm Birth Complications

The lifesaving difference these drugs make

Nurse tending to newborn in incubator
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When a baby is at risk for premature delivery, doctors often give the mother steroids - antenatal steroid treatment - to help the unborn baby's lungs develop more quickly, reducing the risk of serious complications and death. It's quite an effective form of treatment: as little as one day of treatment can make a lifesaving difference.

The drugs betamethatsone or dexamethasone are the two most common types of steroids used in these situations.

Both steroids are smilier and share similar results and side effects. In order to be most effective, steroids should be injected at least 24 hours before the birth of the baby, and preferably no more than 1 week before the baby is born.

Hot Steroid Injections Work

Steroids, short for corticosteroids, are synthetic forms of natural human hormones. When a pregnant woman is injected with steroids, the bloodstream transports the medication to the baby's body. It helps the baby's lung development in several ways:

  • It increases surfactant production. Steroids increase the amount of surfactants that a premature baby's lungs produce. Surfactants helps the lungs to stay open, but premature babies often do not produce enough.
  • It reduces fluid in the lungs. The lungs don't work as well when the lungs are filled with fluid. Steroids can help babies clear fluid out of their lungs more effectively.
  • It increases lung volumes. Babies exposed to steroids around the time of delivery have more lung tissue. Babies with larger lung volumes are able to oxygenate their blood more easily.

    Almost all doctors agree that at least one course of steroids should be given to a mother who is at high risk for premature labor. There is some research that shows that the effects of the steroids diminish after one week, so a repeat course of steroids may be given if the baby is not born within a week.

    Side Effects of Steroid Therapy

    Studies have shown that when pregnant women take a course of steroids - two injections given 24 hours apart - there are no adverse side effects of newborns. In fact, studies that have monitored the development of premature babies into childhood or adulthood have not found differences in development between babies who received steroids and babies who did not.

    Side effects are more common if more than one course of steroid therapy is administered. More than one course is known to cause children to be somewhat smaller than other children who didn't receive treatment. Regardless, they catch up in size to the other children in a matter of months. There is no evidence of any long-term negative consequences of steroid therapy.

    Additionally, there is no evidence that suggests serious side effects among pregnant women. Approximately 1 out of 100 women who underwent a second course of steroid therapy reported temporary sleeping problems shortly after birth. However, it's typical for women who haven't underwent steroid therapy deal with sleeping problems after giving birth.

    See Also


      Bonanno, Clarissa MD, Fuchs, Karin MD, Wapner, Ronald J. MD. "Single Versus Repeat Courses of Antenatal Steroids to Improve Neonatal Outcomes: Risks and Benefits. Obstetrical and Gynecological Survey April 2007; 62, 261-271.

      Informed Health Online. Pregnancy and birth: Before preterm birth: What do steroids do? (2014, February 1).

      Morgan, Maria Ph.D., Goldenberg, Robert MD and Schulkin, Jay Ph.D. “Obstetrician-Gynecologists’ Screening and Management of Preterm Birth.” Obstetrics and Gynecology July 2008; 112, 35-41.

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