Antenatal steroid therapy before 33 weeks' gestation

The purpose of this study was to determine those factors influencing contemporary antenatal steroid use in pregnancies delivered prior to 33 weeks of gestation.

We analyzed the clinical circumstances of 86 consecutive patients who delivered prior to 33 weeks of gestation and compared to 20 women who received dexamethasone prior to delivery with the remaining 66 untreated cases.

Known risk factors for preterm delivery (e.g. prior preterm birth, n = 17; prior admission and tocolysis during the index pregnancy, n = 15) did not discriminate between treated and untreated subsets. Premature membrane rupture (3/20 vs. 34/66; P < 0.01) and documented preterm labor (1/20 vs. 23/66 P < 0.01) were more common in the untreated cohort and a shorter mean interval from admission to delivery was also observed (2.8 vs 11.2 days). However, a full course of steroids would have been possible in 22/66 untreated women, since delivery was delayed for at least 36 h in these patients.

These observations reflect the fact that many preterm births cannot be anticipated, even among hospitalized patients. We would therefore suggest that universal steroid treatment be considered for all women with documented preterm labor prior to 33 weeks of gestation. Initiation of steroid therapy at the referral center, (prior to maternal transport) should also be considered. Since both premature membrane rupture and early gestational age (24-28 weeks') confounded many of these cases, steroid use in patients with these circumstances should be reevaluated.