Body temperatures of very low birth weight infants on admission to a neonatal intensive care unit

Objective: Hypothermia occurs frequently in the first minutes after birth in preterm infants. Hyperthermia also occurs, often as a consequence of efforts to provide thermal support. Both hypothermia and hyperthermia are potentially harmful. Our objective was to examine the distribution of admission temperatures of very low birth weight (VLBW) infants, the effect of gestational age on admission temperatures, and the time required for correction of low temperatures.

Methods: Admission axillary temperatures were retrieved from the medical records for all VLBW infants born in our hospital during a 5-year period. The temperatures were classified as severe (<35.0?°C), moderate (35.0–35.9?°C), or mild (36.0–36.4?°C) hypothermia, normothermia (36.5–37.4?°C), or hyperthermia (≥37.5?°C). The relationship between gestational age and admission temperature was examined. In addition, we analyzed the time required for normalization of low temperatures.

Results: Overall, 12% of infants were severely hypothermic, 40% moderately hypothermic, 27% mildly hypothermic, 19% normothermic, and 2% hyperthermic. Gestational age was inversely related to hypothermia risk and to the time required for recovery to normothermia.

Conclusion: Admission hypothermia is common among VLBW infants and is affected by gestational age.