Urinary excretion of epidermal growth factor in the newborn.

Urinary epidermal growth factor (EGF) excretion was studied serially in 36 newborn infants, from 26 to 40 weeks gestation, from birth to three months of age. All infants excreted EGF from birth. Excretion was significantly higher in term infants than in preterm infants at birth; in term infants excretion rose steadily in early infancy and there was a similar but delayed rise in EGF excretion by preterm infants. Urinary EGF excretion appears to be related to age from conception and birth does not influence it. There was no correlation between urinary EGF excretion and the rapid maturation of the lungs and skin which occurs in preterm infants in the early neonatal period.