This article reviews several different aspects of corticosteroids in preterm labor (PTL). After a short review of the history of the administration of corticosteroids for preterm labor, we review the overall data on PTL.
The next paragraph is on repeated courses of corticosteroids in PTL. Most of the literature does not show benefits from such repeated dosages. Furthermore, some like the large multiple courses of antenatal corticosteroids (MACS) study showed that repeated dosages resulted in smaller babies. What was probably more important was that it resulted in small head conferences, most likely reflecting smaller head sizes.
There is ample literature on the effect of corticosteroids on different organ systems. We do not have good data on the long-term outcomes of this effect. A very long-term study on the original study of Liggins showed some effect on glucose tolerance but no effect on frank diabetes. It is difficult to use these issues in determining the need for corticosteroids as there is always a concern that a long-term effect may be found years later (look at the ORACLE study mentioned here).
There is limited information on the effect of corticosteroids in the late preterm labor. The data is summarized in a table. Two of these papers are on administrating corticosteroids prior to a cesarean section (CS) and are discussed separately. Of the studies on the administration of corticosteroids for late PTL, one stands out. It was done by the maternal fetal medicine (MFM) network in the US, it is large and well-designed. It showed a decrease in both respiratory distress syndrome (RDS) by close to 50% and shortened the stay in the neonatal intensive care unit (NICU) by an average of 8 days. The price was an increase in GDM.
These were the reasons that both the society of maternal fetal medicine (SMFM) and American College of Obstetricians and Gynecologists (ACOG) recommended the use of corticosteroids in late preterm. No other society came forward with such recommendations probably because of the concern for long-term effects.