[Physiologic jaundice in preterm newborns (author's transl)].

Jaundice appearing in the first 24 hours of life, usually called early jaundice, is regarded as pathologic. On the opposite, one of the defining criteria of physiologic jaundice is its' occurrence after the first day of postnatal life. Authors, starting from repeated clinical observations of early jaundice of unknown etiology in preterm newborns, bring about a retrospective study of 1,527 clinical records in order to identify the cases of early jaundice of unknown origin. After known early jaundice-producing causes were excluded, 11 "unknown origin" cases were left. On comparing them with 11 other cases of similar characteristics (gestational age, weight at birth, year and season) who had presented physiologic jaundice, it turned out that the evolution of jaundice was comparable in both groups, except for age of appearance. Early jaundice group bilirubinemia was X = 7.4 (SD +/- 1.59 mg./dl. at 14 (+/- 6.6) hours of age, and physiologic jaundice group bilirubinemia was X = 9.8 (SD +/- 2.25) mg./dl. at 53 (+/- 21.3) hours at age. Since according to selection criteria both groups were made up by healthy preterm newborns, without any perinatal pathology, a study of the drugs administered to the mothers within 24 hours prior to birth was performed: not any reason for early appearance of jaundice was found. Authors' hypothesis support that the chronological criteria used to define physiologic jaundice in full-term newborns cannot always be applied to preterm newborns.