Some parameters of lymphocyte antibody activity through pregnancy and further eluates of placental material.

One hundred and sixty-nine pregnancies with lymphocyte cytotoxic antibody activity were found out of 851 full term pregnancies. A rise in incidence of antibody activity was found through first, second and third pregnancies. The average scores for antibody titre and avidity were similar for antibodies to the A and B loci in first, second and third pregnancies though individual scores varied greatly. Five cases are reported where antibody activity was not detectable till the 6-month post-natal stage. ABO compatibility did not have any effect on antibody production. A further 40 placental eluates are reported with the same findings as reported previously.