Season of birth and early neonatal events. The rise of serum bilirubin

A prospective study on the rise of serum bilirubin during the first 24 hour s of life has been carried out in a sample of 343 newborns from the populat ion of Rome. The rise of serum bilirubin level during the first 24 hours of life depends on season of birth showing a minimum in the Autumn. The pheno menon is much more marked in female than in male newborn infants. Recent st udies suggest a beneficial action of bilirubin due to its protective effect from secondary oxidants. Since the newborn infant is very sensible to oxid ative damage, it is possible that seasonal variation of bilirubin level dur ing the first few days of life may influence further development and suscep tibility to pathological manifestations.