[Physiological changes in serum procalcitonin concentrations in premature infants early after birth]

To investigate serum procalcitonin (PCT) concentrations in premature infants with different gestational ages at different times after birth.

A total of 217 neonates without infection, including 102 premature infants and 115 full-term infants, were enrolled in this study. The premature infants were further divided by gestational age into three subgroups: 30-32 weeks (n=30), 33-34 weeks (n=35) and 35-36 weeks (n=37). All the infants were studied to evaluate serum PCT concentrations at 0-12, 13-24, 25-36, 37-48, 49-72, 73-96, 97-120 and 121-144 hours after birth.

In the newborns, serum PCT concentrations increased gradually after birth, reached peak values at about 24 hours after birth, and then gradually declined and dropped to normal values for children at about 96 hours after birth. In the premature infants, serum PCT concentrations reached peak values at about 36 hours after birth, later than in the full-term infants, then declined slowly and dropped to levels similar to the full-term infants at 96 hours after birth. Serum PCT concentrations in the 30-32 week subgroup remained at low levels after birth, and increased gradually, later than in other premature infants, at 37-48 hours after birth.

Early after birth, neonates have a changing serum PCT concentration, increasing first and then decreasing. Peak serum PCT levels appear later in premature infants than in full-term infants. Serum PCT concentrations of premature infants with a gestational age of under 32 weeks remain at relatively low levels within 36 hours after birth.