Massive Invasion of Fetal Lymphocytes into the Mothers Blood at Induced Abortion

The proband, a healthy primipara, selected for study after she had asserted that she had not previously been pregnant, gave birth to a healthy girl with the karyotype 46.XX In the 21st week of gestation, leukoagglutinin stimulated mitoses from die proband's blood were 99% 46,XX and l% 46.XY. the Y chromosome being identified by its quinacrine fluorescence In two samples taken later in pregnancy no XY mitoses were found in the cultures, but on all three occasions brightly fluorescent Y chromatin in a proportion of the uncultured lymphocyte nuclei showed the presence of XY cells in the proband's blood. High titers of cytotoxic anti‐HL‐A 3 were detected in the maternal serum before and after delivery. Our tentative interpretation is that the XY cells in the proband's blood emanated from a previous fetus that was legally aborted by curettage on the 10th week of an uneventful pregnancy and which the patient admitted to only after repeated questioning.