Effect of Timing of the First Bath on a Healthy Newborn's Temperature

To determine if a healthy newborn's age in hours (3, 6, or 9 hours after birth) affects thermoregulatory status after the first bath as indicated by axillary and skin temperatures.

Quasi-experimental, mixed-model (between subjects and within subjects) design with hours of age as the nonrepeated variable and prebath and postbath temperatures as the repeated variables.

Family-centered care unit at an urban hospital in the southwestern United States.

Healthy newborns (N = 75) 37 weeks or more completed gestation.

Mothers chose time of first bath based on available time slots (n = 25 newborns in each age group). Research nurses sponge bathed the newborns in the mothers' rooms. Axillary temperature, an index of core temperature, was measured with a digital thermometer, and skin temperature, an index of body surface temperature, was measured with a thermography camera. Temperatures were taken before the bath; immediately after the bath; and 5, 30, 60, and 120 minutes after the bath. Immediately after the bath, newborns were placed in skin-to-skin care (SSC) for 60 or more minutes.

We found a difference (p = .0372) in axillary temperatures between the 3- and 9-hour age groups, although this difference was not clinically significant (0.18 °F [0.10 °C]). We found no statistically significant differences in skin temperatures among the three age groups. Regardless of age group, axillary and skin temperatures initially decreased and then recovered after the bath.

For up to 2 hours postbath, axillary and skin temperatures were not different between healthy newborns bathed at 3, 6, or 9 hours of age. Thermography holds promise for learning about thermoregulation, bathing, and SSC.