Recent clinical trials have brought major changes to recommendations from ACOG and other groups on preterm birth (PTB) management. Two of the most important changes recommend the use of steroids at 23 weeks and at 34-36 weeks to reduce the risk of preterm delivery.
“All of these changes in practice recommendations will have a real impact on preterm birth,” predicted Uma Reddy, MD, MPH, Pregnancy and Perinatology Branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development at the National Institutes of Health.
Dr. Reddy discussed the latest recommendations in PTB screening and treatment during a Saturday clinical seminar.
“We have already seen a significant decrease in preterm births since a high of 12.8 percent in 2006,” she said. “Preterm birth fell to 11.4 percent in 2013, the last year for which we have complete data. We have had a positive impact in reducing preterm birth.”
Substantial declines in late preterm birth between 34 and 36 weeks largely led the overall decline in preterm birth, down from 9.15 percent in 2006 to 7.99 percent in 2013. Early preterm birth before 34 weeks declined only slightly, from 3.66 percent to 3.4 percent.
New recommendations on early use of steroids could produce major improvements in early preterm birth. One of the most significant changes is the early use of corticosteroids. ACOG and the Society for Maternal-Fetal Medicine (SMFM) now suggest considering a single course of steroids for pregnant women starting at 23 weeks who are at risk for preterm birth within seven days.
The 2015 consensus statement on periviable birth is based on a cohort study of 23 U.S. academic perinatal centers. Infants born at 23 to 25 weeks who received antenatal steroids had lower rates of death and lower rates of neurodevelopmental impairment at 18 to 22 months.
A 2016 SMFM statement also recommends betamethasone in singleton pregnancies between 34 and 36 weeks in women at risk for preterm birth, a statement based on results of the Antenatal Later Preterm Steroids (ALPS) trial reported earlier this year by the Maternal-Fetal Medicine Units Network. Dr. Reddy noted that ACOG is preparing a similar statement.
The trial showed reduction in the need for respiratory support, reduction in severe respiratory complications, decreased transient tachypnea, bronchopulmonary dysplasia, and the need for postnatal surfactant. There was no increase in neonatal sepsis, chorioamnionitis, or endometritis, but hypoglycemia was more common in infants exposed to betamethasone.
For women in preterm labor, wait for cervical dilation of at least three centimeters or effacement of at least 75 percent before administering with betamethasone. Tocolysis is not recommended to delay delivery, and betamethasone should not be used unless there is a definitive plan for late preterm delivery.
Hospitals should utilize standard guidelines for the assessment and management of neonatal hypoglycemia in late preterm newborns, the statement cautions. And the ALPS protocol should not be implemented for conditions not studied in the trial unless it is part of research or quality improvement.
The new recommendations are an addition to older recommendations that all pregnant women between 24 and 34 weeks who are at risk for preterm delivery within seven days receive a single course of corticosteroids. A single rescue course should be considered if a prior course was given at least seven days earlier and the woman remains at risk for preterm birth before 34 weeks.