Abstract: | We established the percentage of thymus-derived lymphocytes associated with cellular immune responses and bone marrow-derived, antibody-producing cells in maternal blood throughout normal gestation. The data are in conflict with a recent proposal that reversal ot the T:B cell ratio associated with the serum human chorionic gonadotrophin peak of early pregnancy assists in fetoplacental allograft acceptance. Moreover, variability on lymphocyte dynamics in four women followed up serially throughout pregnancy, as well as T- and B-cell determinations in 15 patients whose pregnancy complications are potentially related to maternal-fetal immunologic aberrations, suggests that more sensitive immunologic methods of monitoring the host immune response are necessary to be clinically useful in obstetrics. |