Benefits of prenatal steroids seen beyond 7 days.(Obstetrics)

RENO, NEV. -- A single course of prenatal steroids given to hasten fetal lung maturity is effective for longer than 7 days, meaning there may be no need for a repeat, rescue dose, Alan M. Peaceman, M.D., said at the annual meeting of the Society for Maternal-Fetal Medicine.

In a review of 162 infants whose mothers had received a single, full course of prenatal steroids and who were born before 34 weeks' gestation, the only significant difference between those born within 7 days of the treatment and those born after 7 days was a greater need for ventilatory support.

"I think we need to reexamine our assumption that steroids lose their benefit after 7 days," he said in an interview.

In 2000 a National Institutes of Health consensus panel recommended against the practice of repeat courses of prenatal steroids when a patient at risk for premature delivery did not deliver within 7 days of the treatment because of the possible risks associated with multiple courses.

It is not uncommon, however, for some physicians to use a single, repeat "rescue" course when delivery seems imminent and 7 days have elapsed, or for physicians to hold off giving the initial course until just before they think the patient will deliver, said Dr. Peaceman of the department of maternal-fetal medicine at Northwestern University, Chicago.

The evidence offered by his review of cases is not as definitive as that of a prospective trial, he said, but it does suggest one could give a single course at 24 weeks, as guidelines suggest.

"I'm not recommending anything," Dr. Peaceman said in the interview. "But that is what the data are leaning toward: That there is no point in waiting" until closer to a patient's expected delivery date. Similarly, there is no need to give a repeat or "rescue" dose after 7 days if the patient still has not delivered.