Administering corticosteroid drugs to pregnant women who are at risk for premature delivery increases the chances of survival for their newborns, according to a review of studies.

“The evidence from this new review supports the continued use of a single course of antenatal corticosteroids to accelerate fetal lung maturation in women at risk of preterm birth,” write co-authors Dr. Devender Roberts and Dr. Stuart Dalziel, who said this treatment “should be considered routine for preterm delivery with few exceptions.”

Side effects were not the problem some have feared. Roberts said the review “shows the results of 30-year follow-up studies on the children treated with antenatal corticosteroids and there do not appear to be any statistically significant dangers associated with the use of a single course of steroids.” Roberts is a consultant obstetrician with the Liverpool Women’s National Health Service Foundation Trust in England.

The review appears in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.

The authors reviewed 21 studies that included 3,885 women given either a single course of corticosteroid medication in two doses 12 hours apart or placebo at various points in their pregnancies before delivering prematurely. The women had either gone into premature labor, had early rupture of their membranes or had elected to deliver early in their pregnancy.

Infants whose mother received the corticosteroids had a significantly lower risk for neonatal death, respiratory distress syndrome, brain hemorrhage and digestive disturbances. Lower rates of intensive care admissions, respiratory support and infections in the first two days of life were also seen in the corticosteroid group.

According to the March of Dimes, approximately 12 percent of U.S. pregnancies end in premature delivery, which often results in breathing, brain, and digestive complications in the newborn and in many instances, death within days of birth.

A particularly common complication in premature infants is respiratory distress syndrome (RDS), an often fatal condition resulting from insufficient levels of surfactant, a foamy fluid substance produced by the body between the 34th and 37the week of pregnancy. The substance is essential for the expansion of the air sacs of the lungs.

The review looked at studies of three corticosteroids are used to treat respiratory distress: betamethasone, dexamethasone and hydrocortisone. “The studies in this review mostly used a regime of 12 mg betamethasone 12 hours apart and this is the dose we recommend,” Roberts said. “Betamethasone results in a greater reduction in RDS; therefore it should be the drug of choice.”

Michael Lu, M.D., of the medical school at the University of California, Los Angeles, said, “One major concern with the use of antenatal corticosteroid in the past has been the potential increase in the risks for immunosuppressive side effects.” He added, “There is definitely a need for more long-term follow-up studies.”

The mothers themselves did not experience benefits or side-effects from the medication. For infants, the corticosteroid betamethasone appeared to afford the most benefit.

Researchers do not fully understand what factors put women at risk for preterm delivery, although women who have had a previous preterm birth; women who are pregnant with twins, triplets or more and women with certain uterine or cervical abnormalities appear to be at greater risk.

Half of all premature deliveries, however, occur in women with no known risk factors, and in the United States alone, more than 1,300 infants are born prematurely daily, according to the March of Dimes. In some cases, certain medications can be used to stop the delivery process.

“There is no need for further trials of a single course of antenatal corticosteroids versus placebo in singleton pregnancies,” the authors write. “Follow-up studies in adulthood should be undertaken to confirm the long-term effects of this treatment.”

Roberts D, Dalziel S. Antenatal corticosteroids for accelerating fetal lung maturation for women at risk of preterm birth (Review). The Cochrane Database of Systematic Reviews 2006, Issue 3.

Health Behavior News Service