Technical Update No. 438: Antenatal Corticosteroids at Late Preterm Gestation

Abstract

ObjectiveTo update recommendations for administration of antenatal corticosteroids in the late preterm period. Target PopulationPregnant individuals at risk of preterm birth from 340 to 366 weeks gestation. OptionsAdministration or non-administration of a single course of antenatal corticosteroids at 340 to 366 weeks gestation. OutcomesNeonatal morbidity (respiratory distress, hypoglycemia), long-term neurodevelopment, and other long-term outcomes (growth, cardiac/metabolic, respiratory). Benefits, Harms, and CostsAdministration of antenatal corticosteroids from 340 to 366 weeks gestation decreases the risk of neonatal respiratory distress but increases the risk of neonatal hypoglycemia. The long-term impacts of antenatal corticosteroid administration from 340 to 366 weeks gestation are uncertain. EvidenceFor evidence on the neonatal effects of antenatal corticosteroid administration at late preterm gestation, we summarized evidence from the 2020 Cochrane review of antenatal corticosteroids and combined this with evidence from published randomized trials identified by searching Ovid MEDLINE from January 1, 2020, to May 11, 2022. Given the absence of direct evidence on the impact of late preterm antenatal corticosteroid administration on neurodevelopmental outcomes, we summarized evidence on the impact of antenatal corticosteroids across gestational ages on neurodevelopmental outcomes using the following sources: (1) the 2020 Cochrane review; and (2) evidence obtained by searching Ovid MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases from inception to January 5, 2022. We did not apply date or language restrictions. Given the absence of direct evidence on the impact of late preterm antenatal corticosteroid administration on other long-term outcomes, we summarized evidence on the impact of antenatal corticosteroids across gestational ages on other long-term outcomes by combining findings from the 2020 Cochrane review with evidence obtained by searching Ovid MEDLINE for observational studies related to long-term cardiometabolic, respiratory, and growth effects of antenatal corticosteroids from inception to October 22, 2021. We reviewed reference lists of included studies and relevant systematic reviews for additional references. See Appendix A for search terms and summaries. Validation MethodsThe authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix B (Tables B1 for definitions and B2 for interpretations of strong and conditional [weak] recommendations). Intended AudienceMaternity care providers, including midwives, family physicians, and obstetricians. SUMMARY STATEMENTS1.Evidence suggests that antenatal corticosteroid administration at preterm gestation is associated with reduced perinatal morbidity and mortality. The balance of absolute benefits and harms of antenatal corticosteroid administration changes at late preterm gestation compared with earlier gestational ages (moderate).2.Late preterm antenatal corticosteroid administration (i.e., at 340 to 366 weeks gestation) decreases the risk of neonatal respiratory morbidity but increases the risk of neonatal hypoglycemia (high).3.Late preterm antenatal corticosteroid administration in pregnant individuals with pre-gestational diabetes mellitus may worsen neonatal hypoglycemia (low).4.The impact of late preterm antenatal corticosteroids on neurodevelopment and other long-term outcomes remains uncertain (low).5.Further research is needed to determine the optimal dose of antenatal corticosteroids (moderate). RECOMMENDATIONS1.We continue to strongly recommend antenatal corticosteroid administration up to 336 weeks gestation when delivery is expected within 7 days (strong, high).2.We have changed the upper gestational age boundary to which we strongly recommend antenatal corticosteroid administration from 346 to 336 weeks gestation (conditional, low).3.For pregnant individuals at risk of delivery between 340 and 366 weeks gestation, we recommend considering antenatal corticosteroids based on discussion with patients about absolute harms and benefits specific to the gestational week (strong, moderate).4.Between 340 and 366 weeks gestation, we do not recommend antenatal corticosteroids for pregnancies with pre-gestational diabetes in most cases. The greater risk of hypoglycemia in these pregnancies should be considered as part of the discussion on harms and benefits of antenatal corticosteroids (conditional, low).