In discussing icterus neonatorum, it is of great importance to have a clear idea of the definition of icterus in general. The old definition of icterus as a symptom characterized by coloration of the skin, mucous membranes, and fluids of the body by bile pigment requires revision. Since van den Bergh1 introduced the Ehrlich diazo reaction as a test for minute quantities of bilirubin in the blood serum, it is known that icterus may be present without any discoloration of the skin (icterus sine ictero). We stress this point because in the literature on icterus neonatorum the distinction between icteric and nonicteric infants is often made. This division, however, can no longer be made, for it has been shown that every child has icterus at birth, whether the condition is visible or not. Thus, Cserna and Liebman,2 Zamorani,3 Knoepfelmacher and Kohn4 found that the umbilical cord