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' gestation, on admission for the spontaneous onset of labor pains, at 1 minute after placental delivery and on day 7 after delivery were determined using flow 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 significantly 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-immunity.