Use of antenatal steroids in the late preterm period (34-37 weeks) was recommended in new guidelines from the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine for preventing preterm birth in high-risk women. In this exclusive 番茄社区 video, , of the University of Rochester Medical Center, explains the evidence that led to these new guidelines, as well as the benefits and potential risks for mothers and late preterm fetuses.