Prevention of NICU Admission Hypothermia in Moderate- and Late-Preterm Infants

Neonatal hypothermia is a common and preventable cause of neonatal morbidity and mortality. Although hypothermia prevention has been extensively studied in infants <32 weeks' gestation, the authors of few studies have targeted moderate- and late-preterm infants (MLPIs) in the delivery room.

This quality improvement initiative was conducted from June 2019 to June 2023 at the Massachusetts General Hospital NICU and Labor and Delivery Unit. All inborn MLPIs 32 + 0/7 to 36 + 6/7 weeks' gestation admitted to the NICU were included. We expanded thermoregulatory measures typically used in protocols for infants <32 weeks' gestation, including increasing delivery room ambient temperature to 74°F and thermal mattress use. The primary outcome was hypothermia (<36.5°C) after NICU admission. The balancing measure was hyperthermia (≥38 °C).

During the study period, there were 566 inborn MLPIs with a mean gestational age of 34 + 3/7 weeks and a mean birth weight of 2269 g. Special cause variation in neonatal hypothermia incidence was observed with a decrease from a mean baseline of 27% to 7.8% postintervention. Special cause variation was observed in hyperthermia incidence, with an increase from 1.4% to 6.2% postintervention largely initially associated with noncompliance with the protocol for thermal mattress removal.

The expansion of several thermoregulation techniques commonly used in infants <32 weeks' gestation, particularly thermal mattress use, was associated with a decreased incidence of NICU admission hypothermia in MLPIs, with an increase in mild hyperthermia predominantly associated with concomitant polyethylene wrap use.