0901 Antenatal steroids for lung maturation: how many courses?

One has to wonder whether researchers who continue to investigate the potential short-term benefits of antenatal steroids are fully informing parents when they seek permission to administer multiple doses of the drug. Yes, following the initial and subsequent studies which showed the benefit of a single course on lung maturation in preterm infants it is accepted practice to delay delivery and stimulate surfactant development in eligible mother-infant pairs, but given current concerns around potentially-deleterious pre- and post-natal effects on the offspring should one continue to seek optimal intervals for repeat treatment/s? This question becomes even more pertinent when one reviews the excellent outcomes after a single steroid course, as shown in a recent study involving almost 2000 pregnancies in 20 centres and 80 countries (severe RDS in only 7%; BPD, IVH, NEC all ≤1%) i.e. why expose infants to potential harm of repeat intervention when non-respiratory risks are so low and surfactant replacement therapy has largely mitigated the respiratory risks? The abovementioned study involved 2-weekly intervals for repeats of steroid treatment in infants of 25-32 week who had not delivered after 14-21 days and was done in response to other studies that investigated weekly treatment repeats. While some of the latter studies have shown benefits in terms of neonatal outcome, others have not proven to be effective. However, overall a Cochrane meta-analysis concludes that weekly courses reduce occurrence and severity of lung disease and serious infant morbidity, and this no doubt continues to influence neonatal practice. In contrast to the weekly-repeat studies the two-weekly intervention had no beneficial effect vs placebo, and in fact the 937 treated infants showed significantly lower growth in terms of weight, length and head circumference. Similar adverse effects on growth have been shown in weekly-repeat studies, while there have also been reports of increased risk of cerebral palsy and attention deficits. These results, combined with animal data showing myelination effects and long-term studies that have shown that even the single course has effects on glucose homeostasis after 30 years should probably moderate enthusiasm for continued research in this area.

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Lancet 2008; 372: 2094-5 and 2143-51
Lancet 2005; 365:1856-62
Am J Obstet Gynecol 2002; 186: 843-9 and 2004; 190: 588-95