Changes in maternal peripheral T helper 1-type and T helper 2-type immunity during labor

The percentages of Th1 and Th2 cells and the Th1 : Th2 ratios in peripheral blood from 22 patients with a singleton pregnancy at 30 and 36 weeks' gest ation, on admission for the spontaneous onset of labor pains, at 1 minute a fter placental delivery and on day 7 after delivery were determined using f low cytometry. The percentages of Th1 and Th2 cells and the ratio of Th1 : Th2 did not markedly change during 30 weeks' gestation and 1 minutes after placental delivery. However, the percentage of Th2 cells had decreased sign ificantly at 7 days after delivery. In addition, the Th1 : Th2 cell ratios were significantly elevated on day 7 after delivery. Thus, the termination of pregnancy may not be associated with a change in maternal Th1 : Th2-immu nity.