TEMPORAL STRUCTURE OF BODY CORE TEMPERATURE IN TWIN NEWBORNS

On the basis of our previous investigations on rectal temperature in n ewborns, we studied the rhythmic variations of body core temperature i n twins immediately after birth. We studied 8 pairs of healthy full-te rm twins during the first two days of life. Continuous recording of bo dy temperature was performed every 10 minutes for 24-48 hours by a sol id memory recorder (Fiamarker) connected with a disposable rectal prob e. Data were analysed by the single cosinor method and spectral analys is. All the newborns, except one, demonstrated a statistically signifi cant circadian periodicity of body temperature (p<0,001). Acrophases w ere distributed along the 24 h immediately after birth since the synch ronization to the new environment of life was not yet completed. The s pectral analysis of data demonstrated ultradian fluctuations of temper ature in 14 of the newborns. Temperature data in newborn twins should be collected over a time span long enough to allow discrimination betw een the adaptation phase and the beginning of the synchronized span.