Compared to term infants, late preterm infants have a higher risk of morbidity. Betamethasone (BMZ) has been shown to decrease neonatal respiratory distress but has been associated with neonatal hypoglycemia. This study sought to determine clinical risk factors for neonatal hypoglycemia after administration of antenatal late preterm steroids (ALPS). A secondary analysis was performed to assess outcomes associated with a partial course of ALPS.

This was a retrospective study of pregnant patients who delivered between 340/7 and 366/7 weeks of gestational age from October 2017 to September 2020 at our tertiary care medical center and who received one or two doses of ALPS. We excluded patients who had received prior treatment with BMZ, those with pregestational diabetes, a known anomalous fetus, or multifetal gestation. Neonatal hypoglycemia was defined as <30 mg/dL in the first 24 hours and <45 mg/dL after the first 24 hours of life.

About 239 patients met our inclusion criteria. Incidence of neonatal hypoglycemia increased with increasing birthing parent age, with cesarean delivery, and in those who delivered after the onset of labor, regardless of gestational age at delivery. Deliveries that occurred less than 48 hours after the first BMZ dose were more likely to have neonatal hypoglycemia and neonatal intensive care unit (NICU) admission. In an adjusted model, the incidence of hypoglycemia was the highest from 12 to 35 hours after first BMZ exposure.

In patients who delivered prior to a complete course of ALPS, there were higher rates of neonatal hypoglycemia and NICU admissions. In our cohort, hypoglycemia occurred most often when delivery occurred between 12 and 35 hours after BMZ administration. This information may aid in decision-making on whether to offer ALPS to patients who are at higher risk of delivery in less than 48 hours and in postnatal care for neonates exposed to ALPS.

Shorter ALPS exposure to delivery time had increased odds of neonatal hypoglycemia.

Shorter ALPS exposure to delivery time had increased odds of NICU admission.

Delivery 12 to 35 hours after ALPS was associated with the highest risk of neonatal hypoglycemia.

Received: 27 March 2025

Accepted: 22 July 2025

Article published online:
04 August 2025

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