Bilirubin Studies on the Serum of Newborn Infants

Total bilirubin concentration was determined on the sera of a group of newborn in-fants. Results obtained by a direct spectrophotometric method were compared simultaneously with those of a diazo procedure, using a simple spectrophotometer. The results showed close agreement provided that the sera were unhemolyzed. The effect of hemolysis on both methods is discussed. TILE IWTEIIM IXA’fIOX of bilirubin ill the serum of the newl)orml iiifamit is of great imnportance in the estimation of the amount of jaundice pres-emit..Jauli(lice may be caused liv incompatibility in Rll, ABO, or some otiler blood group, or by sepsis, hepatic immaturity, or variety of ller(’ditary defects in biliary coui,jugation. The ol)stetriCai service of the I)istrict of Columbia Gelieral Hos-pital has about 7000 live births a year, or about 133 pci ’ week. Last year ovem 1000 sera of newbormis were analyzed for tile amount of l)ihi-rubiui 1)r(’sent: hence it was important to employ a method both accu-rate anol rapiol. As is generally accepted, when the indirect biliruhin iii the serumu reaches 20 nig./100 mmii., ami exchange tramisfusion to pre-vent keiuuicterus is inolicated. A number of serum bilirubin determina-tions are required both before aii(I after such a transfusion, as a rise of I nmg./l 00 ml. per hour is considered (langerous (1 iii the last few years there have been some rel)orts (2-:5) of replac-imig the classic van (1cm! Bergh reaction with a method of direct reading of the bihirubiui in a spectrophotometer. Since it has been showmi (6-9