164: Antenatal steroids for enhancement of fetal lung maturity after 34 weeks: Lung maturity and antenatal steroids (LUMAS) study


      To determine the effect of antenatal glucocorticoid administration on fetal lung maturity in pregnancies with known fetal lung immaturity between the 34th and 37th weeks of gestation.

      Study Design

      Pregnancies between 34 0/7-36 6/7 weeks undergoing amniocentesis to determine fetal lung maturity were targeted. Women with negative results (TDx-FLM-II < 45 mg/g) were randomized to intramuscular (IM) glucocorticoid injection (6 mg dexamethasone every 12 hours for 4 doses or 12 mg betamethasone every 24 hours for two doses) or no-treatment. A repeat TDx-FLM-II test was obtained one week after enrollment by either amniocentesis or directly at the time of delivery.


      Over a five year period 32 women who met inclusion criteria were randomized. Seven women (3 in the steroid arm and 4 in the no steroid arm) delivered within a week of repeat testing for fetal lung maturity. Ten received IM glucocorticoid and 15 received no-treatment. Women assigned to glucocorticoids had a mean TDx-FLM-II increase in one week of 26.22 + 9.72 (95% CI 15.54-36.9). Women assigned to no treatment had an increase of 9.76 + 2.03 (95% CI 5.41-14.11). The differences between the two groups were statistically significant (p<0.002). Although the study was not powered to detect differences in neonatal outcome, there were two NICU admissions secondary to respiratory distress requiring intubation; both in the no treatment arm. There were no maternal complications.


      A single course of IM glucocorticoids even after 34 weeks in pregnancies with documented lung immaturity can significantly increase the TDx-FLM-II in one week. Patients with negative fetal lung maturity parameters between the 34th-37th weeks can benefit from a single course of steroids. The data suggest a potential to decrease neonatal morbidity and warrants a larger study to assess neonatal outcome.