Overall neonatal morbidity unimproved: multiple steroid courses tied to lower birth weights.(Obstetrics)

NEW ORLEANS -- Repeated weekly courses of prenatal steroids reduce infant morbidity in certain cases, but the overall risks of this approach outweigh the benefits, Dr. Ronald J. Wapner said at the annual meeting of the Society for Maternal-Fetal Medicine.

In a trial of 492 women at 23-32 weeks' gestation who were at risk for spontaneous preterm birth, the use of repeated weekly courses of prenatal steroids did not improve overall neonatal morbidity. In addition, repeated courses led to a reduction in birth weight and an increase in the frequency of small-for-gestational-age infants, compared with babies of women who were given an initial steroid dose followed by placebo doses.

"Based on these observations, we believe that weekly administration of prenatal corticosteroids should not be utilized," said Dr. Wapner of the National Institute of Child Health and Human Development, Rockville, Md.

Study participants were randomized to receive weekly courses of betamethasone or a single dose followed within 10 days by weekly placebo. There were no significant overall differences between groups in these primary outcomes: stillbirth or neonatal death, severe respiratory distress syndrome, grade III or IV intraventricular hemorrhage, periventricular leukomalacia, or chronic lung disease. Among those who delivered before 32 weeks' gestation, however, multiple steroid doses were associated with a trend toward reduction in the risk of the primary outcomes.

Overall, multiple courses were associated with significant reductions in most secondary outcomes related to lung function.

At least one of the primary outcomes occurred in 8% of the 250 women who received weekly steroid doses and 9% of the 242 women in the placebo group.

Among those who delivered before 32 weeks' gestation, at least one of the primary outcomes occurred in 21% of 60 women in the weekly steroid group, and 39% ...