17: Assessing the potential impact of extending antenatal corticosteroid use


      In 2016 ACOG/SMFM issued guidance extending antenatal steroid use for selected late preterm singleton pregnancies based on new evidence for improved neonatal respiratory outcomes. Our objective was to assess antenatal steroid use and the potential impact of these guidelines.

      Study Design

      This cohort study used chart-abstracted data from singleton deliveries at 12 centers participating in the Obstetric Clinical Outcomes Program (OB COAP), a quality initiative in Washington State. Centers contributing data for all or part of the study period (January 1, 2012-March 31, 2016) were included. Pregnancies with missing gestation at delivery, fetal anomalies, or antepartum demise were excluded. Newborn respiratory complications were calculated for pregnancies considered eligible and ineligible for late preterm steroids based on the 2016 guidelines.


      The analytic sample included 60243 singleton deliveries at 24+0-42+6 weeks. Of the 3949 preterm (24+0-36+6 weeks) deliveries, 74.5% (n=2942) were late preterm. Eighty percent (n=2363) of late preterm deliveries were potentially steroid eligible and 60% of these (n=1411) delivered at 36 weeks. Steroid eligible late preterm deliveries represented 4.0% (2363/59236) of all deliveries at >34 weeks. Approximately 80% (248/312) of late preterm newborns with respiratory complications were in the steroid eligible group and of those 69% (171/248) occurred in deliveries at 34-35 weeks. The rate of newborn respiratory complications was highest in those ineligible for steroids due to pre-pregnancy diabetes or chorioamnioninitis regardless of gestational age at delivery.(Table 1) For deliveries at 36 weeks, those eligible for steroids or ineligible due to prior steroids had similar rates of respiratory complications (5.5% vs 4.9%).


      In our study up to 4% of singleton deliveries at >34 weeks could be considered targets for late preterm steroids based on new guidelines. Nearly 3/4 of newborn respiratory complications in this group were in those delivering at 34-35 weeks.
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