In order to "protect" pregnant women who are supposedly at high risk of giving birth prematurely, medical doctors frequently prescribe weekly injections of synthetic hormones known as corticosteroids.

However, a new study, published in the Journal of the American Medical Association (JAMA), has found that the drug does NOT significantly reduce illness among newborn babies, compared to those women who receive far fewer drugs.

Debra A. Guinn, M.D., of the Denver Health Medical Center and the University of Colorado Health Sciences Center, Denver, and colleagues evaluated the efficacy of weekly administration of antenatal (or prenatal) corticosteroids, compared with a single course, in reducing the incidence of disease among newborn infants. The authors also evaluated potential complications of weekly treatment.

Corticosteroids are synthetic hormones often used to treat inflammatory illnesses, including asthma and rheumatoid arthritis.

The treatments are supposed to reduce the incidence of respiratory distress syndrome (RDS, a severe breathing problem that is very common in premature babies at high risk for preterm delivery); intraventricular hemorrhage (IVH, bleeding from fragile blood vessels in the brain); and mortality in premature newborn infants.

The authors conducted tests on some 500 pregnant women who were at high risk of preterm delivery.

All patients received a complete single course of antenatal corticosteroids by injection. Those who did not give birth within a week of receiving the single course, were randomly divided up into groups. One group received weekly doses of the drug while the other received a placebo.

There was no significant difference between the number of deaths and health problems in the babies delivered.

However, the weekly treatment had far more dangerous side effects, including a possible increase risk of cerebral palsy, the authors noted.

While this study was being conducted, other reports were coming in regarding the potential for long-term neurological complications associated with weekly courses of antenatal corticosteroids to humans.

"Given the apparent lack of efficacy and the potential for short- and long-term neurologic damage resulting from weekly administration," wrote the authors, "we elected to 'do no harm' and stop the study prematurely."

"Our data strongly suggest that weekly courses of antenatal corticosteroids should not be prescribed routinely for women at risk of preterm delivery," they concluded.

SOURCE: Journal of the American Medical Association (JAMA), October 3, 2001.