Skin microcirculation before and after local warming in infants delivered vaginally or by caesarean section

To elucidate early postnatal changes in skin microcirculation, term newborn infants were studied at 2, 6 and 24 h after vaginal delivery (VD, n = 20) or elective caesarean section (CS, n = 10). Laser Doppler technique was used to measure perfusion, rhythmical perfusion changes, i.e. vasomotion, and reactive hyperaemia of the dorsal hand, before and after local warming of the skin to 37 degrees C. The skin perfusion and the magnitude of reactive hyperaemia (mean 85%) remained essentially unchanged, while vasomotion increased from 0-5 to 2-8 cycles/min (p < 0.001) during the first day of life. Local warming of the skin promoted microcirculation slightly at 2 h and more markedly at 24 h postnatal age. The CS group showed a higher degree of skin perfusion, vasomotion and reactive hyperaemia than did VD infants at 2 h postnatal age. Our findings most likely reflect skin microcirculatory effects of birth-related events, such as a drop in body temperature, sympathoadrenal activation and placental transfusion.