Effects of gestational and postnatal age on body temperature, oxygen consumption, and activity during early skin-to-skin contact between preterm infants of 25-30-week gestation and their mothers

Temporary skin-to-skin contact between preterm infant and the mother is increasingly used in neonatal medicine to promote bonding. It is not known at which gestational age (GA) and postnatal age skin-to-skin contact outside the incubator is a sufficiently warm environment and is tolerated by preterm infants without a decrease in body temperature, oxygen consumption (Vo(2)) increase, or unrest. We conducted a prospective clinical study of 27 spontaneously breathing preterm infants of 25-30-wk GA. Rectal temperature (T-rectal), Vo(2) (indirect calorimetry), and activity were continuously measured in the incubator (60 min), during skin-to-skin contact (60 min), and back in the incubator (60 min) in wk 1 and 2 of life. In wk 1 the change in T-rectal during skin-to-skin contact was related to GA (r = 0.585, p = 0.0027): infants of 25-27-wk GA lost heat during skin-to-skin contact, whereas infants of 28-30 wk gained heat and their mean T-rectal during skin-to-skin contact was 0.3 degrees C higher than before (p < 0.01). No significant changes of Vo(2) or activity occurred. In wk 2 the infants' Vo(2) was higher than in wk 1, but Vo(2) during skin-to-skin contact was the same as in the incubator. Only small fluctuations in T-rectal occurred. In wk 2 all infants slept more during skin-to-skin contact than in the incubator (p < 0.02). We conclude that, for preterm infants of 28-30-wk GA, skin-to-skin contact was a sufficiently warm environment as early as postnatal wk 1. For infants of 25-27-wk GA skin-to-skin contact should be postponed until wk 2 of life, when their body temperature remains stable and they are more quiet during skin-to-skin contact than in the incubator.