A single course of corticosteroids is currently recommended by the American College of Obstetricians and Gynecologists (2017a) for women between 24 and 34 weeks who are at risk for delivery within 7 days. This recommendation for premature twins has been challenged (Viteri, 20e16). Boundaries of gestational age for corticosteroid administration are also now being explored. For pregnancies at 23 weeks and at risk of delivery within 7 days, a single course of corticosteroids may be considered (p. 807). Administration of corticosteroids during the periviable period is linked to a family's decision regarding resuscitation and should be considered in that context (American College of Obstetricians and Gynecologists, 20e1e7e).
Betamethasone and dexamethasone appear to be equivalent for fetal lung maturation (Murphy, 2007). These two drugs are comparable in reducing rates of major neonatal morbidities in preterm newborns (Elimian, 2007). A treatment course may be two 12-mg doses of betamethasone, and each dose is given intramuscularly 24 hours apart. With dexamethasone, 6-mg doses are given intramuscularly every 12 hours for four doses. Because treatment for less than 24 hours may be beneicial and reduce neonatal morbidity and mortality rates, a first dose of antenatal corticosteroids is administered regardless of the ability to complete additional doses before delivery (American College of Obstetricians and Gynecologists, 20e1e7a).
The MFMU Network conducted a randomized trial to assess whether administration of antenatal betamethasone to women who were likely to deliver in the late-pre term period would
Bannerman, 2016). Even though only 60 percent of the study cohort of 283e1 women received both injections, the rate of respiratory complications measured as a composite outcome was lower with corticosteroid use compared with placebo-1 1.6 versus 14.4 percent. Because of these indings, consideration for administration of a single course of betamethasone for women the American College of Obstetricians and Gynecologists (2017a) and the Society for Maternal-Fetal Medicine (2016a).
Adoption of this practice has not been universal. Both shortand long-term neonatal safety are concerns (Crowther, 2016; Kamath-Rayne, 2016). Specifically, in the newborns receiving betamethasone, rates of hypoglycemia were signiicantly greater (Gyami-Bannerman, 20e16) . Neonatal hypoglycemia is particularly worrisome for possible adverse long-term consequences that include developmental delay (Kerstjens, 2012). Another caveat is that the largest efects of betamethasone included a reduction in transient tachypnea of the newborn-a self-limited condition with little clinical signiicance (KamathRayne, 2016). Speciically, the rates of transient tachypnea of the newborn were 6.7 and 9.9 percent in those given betamethasone and placebo, respectively. These rates are three-to fourfold higher than those reported by the Consortium on Safe Labor (20e10), which was a retrospective, observational study that abstracted detailed labor and delivery information from 19 hospitals across the United States on 233,844 deliveries. Because of these issues, we do not provide corticosteroids beyond 34 weeks at Parkland Hospital at this time.