Current controversies surrounding the use of repeated courses of antenatal steroids.

The use of a single dose of antenatal steroids to facilitate fetal lung maturation in the expectant management of threatened preterm birth has significantly improved the mortality and morbidity of premature infants worldwide. In some settings, the evidence for this practice has been extrapolated with self-reports of up to 6 repeated courses during the antepartum period. Concerns about the use of repeated antenatal courses prompted the National Institutes of Health (NIH) to publish a consensus statement (2000) that reaffirmed the safety and efficacy of a single course of antenatal steroids, but emphasized that there are no data to support the safety and efficacy of repeated courses. The statement cautions against the use of multiple courses outside of research protocols. Despite these recommendations, wide variations in clinical practice continue to exist. There are growing concerns about the potential deleterious effects of steroid exposure on the developing human brain. It is plausible, although not proven, that negative neurodevelopmental impact may occur, or be compounded by multiple antenatal or combined antenatal and postnatal steroid exposures. This article provides a review of the evidence to support appropriate steroid use. The physiology and pharmacology of both endogenous and exogenous steroids are outlined to enhance the clinician's understanding of these potent agents. Recommendations for targeted clinical evaluation and short- and long-term follow-up of steroid exposed infants are provided. A clear understanding of the known and potential risks and benefits of single and multiple courses of antenatal steroids is essential to prompt a critical re-examination of the safety and efficacy of repeated steroid exposure in the neonate.