Sixty-eight infants under 2 weeks of age have heen admitted to the department of pediatric surgery in the last 4 years. Nineteen infants (28%) developed neonatal hyperbilirubinemia (NHB) and were treated with the phototherapy and/or exchange transfusion. During the last 1 year, 500 infants have been born in our hospital. Seventy (14%) of this group developing pathological jaundice were treated in the same manner. The incidence of NHB was statistically much higher in surgical group than in non-surgical group (p < CO. 005). In the surgical group, eight of 12 low birth weight infants (67%) developed NHB. On the other hand, 11 of 56 infants (20%) weighing more than 2,500g developed NHB (p < 0.005). The surgically treated infants were divided into two groups : gruop I was composed of 47 infants with gastrointestinal obstruction and group II was composed of 21 infants without gastrointestinal obstruction. The incidence of NHB was 30% in group I and 24% in group II. However, there was no significance in these two groups. Five infants of group I were complicated with perforation of the gastrointestinal tract and peritonitis. Three of these 5 infants showed NHB. Therefore it is suggested that the perforation and peritonitis increase the risk for NHB. Seven of 17 infants (41%) with severe dehydration, in whom percent weight loss was more than 10, developed NHB. On the other hand, NHB was found in only 12 of infants (24%) associated with mild or moderate dehydration. Although there was no statistical significance, it is not possible to ignore the fact that severe dehydration is one of the developing factors of NHB. Our own experience indicate that the risk factors of NHB in neonatal surgery are low birth weight, perforation of the gastrointestinal tract and peritonitis, and severe dehydration. The presence of gastrointestinal obstruction may not be risk factors of NHB if dehydration and starvation have been corrected by proper management.
