Late Preterm Corticosteroids and Neonatal Hypoglycemia

This is a prospective randomized controlled trial investigating the timing of betamethasone administration in late preterm infants in relation to delivery and impact on neonatal hypoglycemia. Previous data has shown that neonatal hypoglycemia is increased in late preterm infants that were exposed to antenatal corticosteroids. The investigators hypothesize that the timing of steroid administration may impact the development of neonatal hypoglycemia.

The use of antenatal corticosteroids for women at risk for preterm delivery has become widely adopted as standard of care. The American College of Obstetrics and Gynecologists (ACOG) officially recommends the use of corticosteroids for pregnant women between 24 and 34 weeks of gestation at risk of delivery within 7 days. Since publication of the ALPS trial, the Society of Maternal Fetal Medicine (SMFM) published guidelines supporting the use of late preterm steroids for singleton pregnancies between 34 weeks 0 days and 36 weeks 6 days who are at high risk of preterm birth within 7 days. A secondary finding of the ALPS trial included the observation that the administration of antenatal betamethasone significantly increased the rate of neonatal hypoglycemia; the authors emphasized that while the long-term risks associated with neonatal hypoglycemia are not fully known, significant hypoglycemia is associated with poor neurodevelopmental outcome. The optimal interval for administering late preterm steroids before delivery to minimize the risks of hypoglycemia while maximizing the benefits of fetal lung maturity has not been identified. The proposed research study will further investigate this question by randomizing patients to receive late preterm corticosteroids 2 days before delivery versus 7 days before delivery in order to determine if the rates and severity of neonatal hypoglycemia are different.

Drop in oxygen saturation requiring use of CPAP or high flow nasal cannula for at least 12 continuous hours

Drop in oxygen saturation requiring use of supplemental oxygen with a fraction of inspired oxygen (FiO2) of at least 0.30 for at least 24 continuous hours

Drop in oxygen saturation and/or inability to maintain an airway requiring use of mechanical ventilation

Incidence of intrauterine fetal demise at any point after administration of the intervention (betamethasone) and before delivery

Defined as the presence of clinical signs of respiratory distress (ie: tachypnea, retractions, flaring, grunting, cyanosis) with a requirement of supplemental oxygen with a fraction of inspired oxygen of more than 0.21 and a chest radiograph showing hypoaeration and reticulogranular infiltrates

Defined when tachypnea (Respiratory Rate >60 breaths per minute) occurs in the absence of chest radiography or a radiograph that was normal and resolved within 72 hours

Defined when a combination of clinical, microbiologic, and/or radiographic findings suggest primary pulmonary infection as a cause of respiratory distress, fevers, increasing white blood cell count, need for antibiotics, and/or sepsis.

Defined when the extent of brain injury includes a hemorrhage that occupies more than 50% of the lateral ventricle volume

inability to take all feeds by mouth, requiring gavage feeds or intravenous supplementation at least once.

Inclusion Criteria: Singleton pregnancy Gestational age 34 0/7 weeks to 36 5/7 weeks Planned delivery in late preterm period Exclusion Criteria: Prior course of betamethasone during pregnancy Twin gestation Fetal demise Major fetal anomaly Maternal contraindication to betamethasone Pregestational diabetes Expected delivery within 12 hours of randomization

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Society for Maternal-Fetal Medicine (SMFM) Publications Committee. Implementation of the use of antenatal corticosteroids in the late preterm birth period in women at risk for preterm delivery. Am J Obstet Gynecol. 2016 Aug;215(2):B13-5. doi: 10.1016/j.ajog.2016.03.013. Epub 2016 Mar 15. No abstract available. Erratum In: Am J Obstet Gynecol. 2017 Feb;216(2):180.

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Uquillas KR, Lee RH, Sardesai S, Chen E, Ihenacho U, Cortessis VK, Barton L. Neonatal hypoglycemia after initiation of late preterm antenatal corticosteroids. J Perinatol. 2020 Sep;40(9):1339-1348. doi: 10.1038/s41372-020-0589-1. Epub 2020 Feb 14.