T and B Lymphocytes during Normal Human Pregnancy: a Longitudinal Study

Abstract

Immunological relationships in pregnancy were investigated in a longitudinal study of 22 pregnant women whose blood samples were taken before pregnancy, during pregnancy, at delivery and 3-5 mo. after delivery. Blood samples were also taken from the fathers and the infants, at birth and after 3-5 mo. All samples were frozen with a cryobiological freezing system, and when a whole longitudinal series had been collected, the material was thawed and tested in a single seance. T [thymus-derived] and B [bone marrow-derived] lymphocytes were studied with rosette tests (E [erythrocyte] and HEAC [human A erythrocytes, rabbit anti-A, mouse complement] rosettes). T and B lymphocytes did not change during pregnancy. The mother''s tolerance of a fetus with a dissimilar tissue type is not exercised via changes in the total count of T and B lymphocytes, although there may well be changes in their subpopulations, with the hypothesis that T suppressor function increases and B lymphocyte function decreases.