RT Journal A1 MITCHELL J T1 ORigin and fate of iso-agglutinins in blood from the umbilical cord JF American Journal of Diseases of Children JO American Journal of Diseases of Children YR 1929 FD May 1 VO 37 IS 5 SP 1008 OP 1015 DO 10.1001/archpedi.1929.01930050118013 UL http://dx.doi.org/10.1001/archpedi.1929.01930050118013 AB The relative frequency with which iso-agglutinins and agglutinogens are found in the blood of the infant at birth and during the early days of life has been investigated frequently. Happ1 found the blood group completely established at birth in 16.3 per cent of forty-nine cases, and McQuarrie2 in 11 per cent of 180 cases. Other authors reported percentages varying from these to 78.7 per cent of 197 cases, the figure quoted by Jones.3All investigators, with the exception of von Decastello and Sturli,4 agreed that the agglutinogens appear earlier and occur in a larger proportion of cases than the iso-agglutinins. A change has never been demonstrated in a blood group which was completely established. Happ 1 and Unger,5 however, pointed out apparent changes in group by the accession of iso-antibodies previously lacking, and Smith6 reported two cases in which the apparent change was caused