Delayed admission temperature normalisation in preterm infants <32 weeks: impact on mortality and neonatal morbidities.

Abstract

Objective: To evaluate the impact of delayed temperature normalisation on neonatal outcomes, including mortality and major morbidities, in preterm infants born at <32 weeks' gestation.

Design: Retrospective cohort study.

Setting: Neonatal Intensive Care Unit at King Abdulaziz Medical City, Riyadh, Saudi Arabia.

Patients: Preterm infants born at <32 weeks' gestation between January 2022 and December 2024.

Main outcome measures: Infants were categorised into three groups based on temperature normalisation: normothermia at admission, early recovery (<2 hours) and late recovery (>2 hours). Primary outcomes included mortality before discharge, major neonatal morbidities (intraventricular haemorrhage (IVH), necrotising enterocolitis (NEC), bronchopulmonary dysplasia (BPD) and culture-positive sepsis) and duration of mechanical ventilation and hospital stay.

Results: Among 578 preterm infants, 75% achieved normothermia at admission, 16% recovered within 2 hours and 9% required >2 hours. Mortality was significantly higher in the late recovery group (42%) versus normothermia (7%) and early recovery (11%) (p<0.001). Late recovery was also associated with higher rates of major IVH (27% vs 5% normothermia, 11% early recovery, p<0.001), surgical NEC (10% vs 2% normothermia, 7% early recovery, p=0.001) and BPD (44% vs 16% normothermia, 42% early recovery, p<0.001). The need for mechanical ventilation was highest in the late recovery group (87%) (p<0.001). Kaplan-Meier analysis demonstrated prolonged ventilation and hospital stay (p<0.001).

Conclusions: Delayed temperature recovery beyond 2 hours is associated with higher mortality and neonatal morbidities. These findings highlight the importance of early thermal stabilisation to improve outcomes in preterm infants.