Short-lived suppressor cell activity during normal human pregnancy.

Short-lived suppressor cell (SLSC) activity was determined in normal pregnant women. This activity was significantly increased in all three trimesters of pregnancy and during the first week postpartum. When pregnant women were divided into primiparous and multiparous groups, no significant differences were found between the two groups in any of the periods studied. These results suggest that increased SLSC activity may play a role in the materno-fetal tolerance and that parity has no influence on this activity.