Maternal peripheral blood lymphocyte subpopulations in normal and pathological pregnancies

Flow cytometry was used to determine lymphocyte subpopulations in maternal blood from 143 pathological pregnancies: 50 with fetal aneuploidy; 32 with missed abortions; 12 with ectopic pregnancies; 20 with multi-fetal pregnancies, and 29 with pregnancies complicated by intrauterine growth retardation (IUGR). The values were compared to those of 240 women with normal singleton pregnancies at 8-40 weeks of gestation and 20 non-pregnant controls. In early pregnancy (8-10 weeks), compared to non-pregnant values, there was a decrease in the percentage of CD4+ cells and CD4+ to CD8+ ratio and an increase in the percentage of CD8+ cells. In later pregnancy, the CD4+ cell percentage and CD4+ to CD8+ ratio increased and the CD8+ cell percentage decreased to reach non-pregnant values at term. The percentage of natural killer (CD3- and CD16/56+) cells decreased with gestation, while the percentage of B (CD19+) cells did not change significantly. In IUGR, the percentage of CD4+ cells and CD4+ to CD8+ ratio were decreased, while the percentage of CD8+ cells was increased. In contrast, in the groups of missed abortions and ectopic pregnancies, the CD4+ to CD8+ ratio was increased. In multifetal pregnancies and those with fetal aneuploidies there were no significant differences in maternal lymphocyte subpopulations from normals.