Long-term analysis of allogeneic prenatal chimeras. (A) Engraftment prevalence at 6 months of age is plotted for each recipient group. Recipients are grouped according to cell dose at transplantation (2 × 10⁴-2 × 10⁶ cells/fetus). (B) PB chimerism level by cell dose in recipients at 6 months of age. Data points represent the mean value plus or minus SEM. (C) Surviving recipients who remained engrafted were killed at 1 year of age (n = 11), and a bone marrow lineage analysis for both donor and host hematopoiesis was performed (*P < .05). Data points represent the mean value plus or minus SEM.