The original randomized trial of corticosteroid (CS) administration for anticipated preterm delivery is nearly 30 years old. Further, it is not likely to be repeated per se since other issues in schedules for CS have emerged in the subsequent decades. While repeated courses of CS administration were based on the notion that the initial effects on pulmonary maturation were short-lived, more recent studies, cited in this paper, have not shown benefits from these strategies. Moreover, there may be some harm (Wapner RJ, Sorokin Y, Mele L, et al: N Engl J Med 2007;357: 1190–1198). This study provides some background work to examine the feasibility of so-called “rescue” administration of CS once an initial course has been completed. This becomes a consideration when pregnancy extends more than 1 week from treatment. While this study suggests that fewer than 1 in 5 pregnancies would qualify, being <34 weeks’ gestation, its greater importance may relate to the subgroup analysis, which identifies the characteristics of patients most likely to fall into these subgroups: twins, PPROM and administration prior to 28 weeks’ gestation. Clearly, more work needs to be done in this area. The benefits of antenatal CS administration is no longer an issue. However, the best recipe for providing this intervention is still uncertain.
Editor's Commentary: As we have ended the first decade of the new millennium, there are a number of unresolved issues in perinatal medicine. The majority of these issues center around the lingering problem of preterm birth. These 2 manuscripts address the poles of antenatal and neonatal interventions that affect birth outcomes. As a profession, we must accept the fact that unintended preterm birth will persist well into the future. Therefore, there must be care plans that will address these events. The premise that maintenance of body temperature will improve outcomes of extremely preterm neonates would qualify as a no-brainer. However, the adoption of a food storage approach to wrapping these infants requires a paradigm shift. Hopefully, the dots will be connected in the future. Should the inevitable outcomes of preterm birth, whether intentional or not, be modified by antepartum therapies? The answer to that critical question remains out there and unanswered by the extant clinical trials. If one chooses to use the principle of biologic plausibility, then antenatal administration of corticosteroids remains open to critical investigation. How long do these effects persist? Should clinicians assess fetal lung maturity at weekly intervals? How soon does antenatal CS improve fetal lung maturity? How long do these effects last? The answers to these questions are either unavailable or are 3 decades old. Rather than dismissing repeated courses of CS to vulnerable fetuses, more work needs to be done to resolve the effect of multiple CS courses. Given the issue that response to antenatal CS is modified by many factors, this becomes the perfect “one size does not fit all.”
