SMFM releases statement on use of antenatal corticosteroids in late preterm birth period

The Society for Maternal-Fetal Medicine released a statement on the use of antenatal corticosteroids during the late preterm birth period for women at risk of preterm birth. The statement, is currently available online and will be published in the July issue of the American Journal of Obstetrics and Gynecology. It comes on the heels of a study and a presentation at SMFM's annual meeting in Atlanta in February where researchers with the Eunice Kennedy Shriver National Institute of Child Health and Human Development and Maternal-Fetal Medicine Units Network (MFMU) presented findings that the administration of antenatal steroids in pregnancies at risk for late preterm delivery prevents respiratory and other neonatal complications.

The study, titled Antenatal Late Preterm Steroids (ALPS): a Randomized Trial to Reduce Neonatal Respiratory Morbidity was a randomized, double-blind, placebo-controlled trial at 17 tertiary medical centers around the United States from Oct. 2010 to Feb. 2015. The study enrolled 2,831 women with singleton pregnancies at high risk for late preterm delivery (34 0/7 to 36 6/7 weeks) who were randomized to receive antenatal betamethasone intramuscularly or a matching placebo. This study found a significant decrease in neonatal respiratory complications in the group given the steroid treatment. Investigators also found that these babies were less likely to have prolonged intensive care nursery stays, less likely to need postnatal treatment for respiratory complications, and less likely to develop bronchopulmonary dysplasia, which is a sign of chronic lung disease. Prior to this report, such treatment was only recommended with risk of preterm delivery before 34 weeks of gestation, as infants in the late preterm period were thought to be at little, if any, increased risk of complications.

Lead investigator, Cynthia Gyamfi-Bannerman, M.D., MSc, the Ellen Jacobson Levine and Eugene Jacobson Associate Professor of Women's Health (in Obstetrics and Gynecology) from Columbia University Medical Center, put the findings in context: "The majority of preterm deliveries occur in the late preterm period. We now have a treatment that can significantly improve outcomes for these at risk babies." The study was co-funded by the NHLBI, with the aid of program officer Carol Blaisdell, M.D. and the NICHD under the guidance of Uma Reddy, M.D.

In their statement, the Society for Maternal-Fetal Medicine recommends:

• In women with a singleton pregnancy between 34 weeks to 36 6/7 weeks of gestation who are at high risk for preterm birth within the next seven days (but before 37 weeks of gestation), SMFM recommends treatment with betamethasone, a corticosteroid demonstrated to decrease neonatal complications in preterm infants.
• In women with preterm labor symptoms in the late preterm period, SMFM recommends waiting for evidence of true preterm labor, such as a cervical dilatation of at least three centimeters or effacement of at least 75% before treatment with betamethasone.
• In women with late preterm pregnancies receiving betamethasone, SMFM recommends against the use of tocolysis in an attempt to delay delivery to complete the steroid course since it is unclear if the benefits are outweighed by the risks of attempts to delay delivery.
• In women with late preterm pregnancies with a potential medical indication for delivery, SMFM recommends betamethasone not be given unless there is a definitive plan for late preterm delivery.
• SMFM also recommends against the implementation of antenatal late preterm steroids protocol for conditions not studied in the randomized controlled trials.

Given that more than 300,000 pregnancies deliver in the late preterm period each year in the U.S., the study along with recommendations for adoption by the Society for Maternal-Fetal Medicine will have a significant impact on the health of newborns and infants.