Reference Ranges for Preductal Oxygen Saturation and Heart Rate in Moderate and Late Preterm Infants with Deferred Cord Clamping.

Introduction: Moderate and late preterm (MLPT) infants represent a substantial percentage of all preterm infants and frequently need support in the delivery room. Deferred cord clamping (DCC) improves SpO2 and heart rate (HR) stabilization in term infants. However, data on MLPT infants are limited.

Methods: We performed a prospective observational study collecting SpO2 and HR by pulse oximetry in healthy MLPT infants with DDC to construct percentile graphs for the first 10 min after birth.

Results: A total of 96 MLPT infants were monitored for preductal SpO2 and HR, and percentiles were calculated. SpO2 mean was significantly lower for MLPT than for term infants during the first 6 min after birth, and 15% did not achieve SpO2 ≥85% in the first 5 min after birth. HR was significantly lower in MLPT infants in the first 4 min after birth; however, HR consistently remained above bradycardic values (>100 bpm). NICU admission and postnatal complications were not different between MLPT achieving SpO2 ≥85% or not.

Conclusion: MLPT infants with DCC achieved stable SpO2 and HR significantly later, 6 min and 4 min, respectively, than term infants. In addition, 15% of MLPT infants did not achieve SpO2 ≥85% at 5 min after birth. However, admission to the NICU and clinical evolution did not differ from newborns with SpO2 ≥85% at 5 min. Larger studies including long-term follow-up are needed to assess if lower SpO2 in the first 5 min has clinical consequences in non-resuscitated MLPT.