The birth process initiates an acute phase reaction in the fetus-newborn infant

Our goal was to investigate whether the normal birth process stimulated an acute phase response in healthy infants with physiological changes in the c irculating levels of acute phase cytokines and acute phase proteins. We als o monitored body temperature, body weight and behavioural state in order to investigate if clinical signs of acute phase reaction were present. We mad e cross-sectional measurements of interleukin-1 beta, interleukin-6, C-reac tive protein, serum amyloid A, procalcitonin, prealbumin, body weight, body temperature and the duration of the sleeping period during the first four postnatal days. We found an increase in interleukin-6 (p < 0.001) during th e first day, followed by an increase in C-reactive protein, serum amyloid A and procalcitonin on the second postnatal day (p < 0.01). The level of pre albumin fell after birth and reached its lowest value at 3 d of age (p < 0. 001). Interleukin-1 beta remained unchanged. The duration of the sleeping p eriod was longer during the first day (p < 0.01). There was an increase in body temperature during the first day (p < 0.01). Maximal weight loss was d uring the first 2 d. Conclusions: The normal birth process and extra-uterine adaptation stimulat es an acute phase reaction in the newborn infant with a release of interleu kin-6 and acute phase proteins and a depression of prealbumin. This reactio n, as the body's first line inflammatory defence system, probably affects: the infant's behaviour, nutritional state as well as the regulation of body temperature.