Specific and cross-reacting antibodies in ABO heterospecific twin pregnancy.

Wit/i the assistance of KATHRYN BEAVFIE T HE SUB.JECT of this report is an unusual experiment of nature imivolving a pair of twins of different A and B blood groups bormi to a group 0 mother. The devebopmemit of frank hemolytic disease in the twin hebongimig to blood group B, in the absence of recognizable abmiormalities imi the group A twin was the indication for a detailed study of the behavior of the anti-A and amiti-B antibodies in the mother amid irs both infants. The observations were designed to throw light on the question of transplacental passage, specificity and mode of actiomi of maternal antibodies in ABO hemolytic disease of the newborn.