Maternal Peripheral T-Helper 1-Type and T-Helper 2-Type Immunity in Nonpreeclamptic Twin Pregnancies

The percentage of T-helper (Th)1, Th2 cells and the Th1:Th2 cell ratios in peripheral blood from 14 normal nonpregnant women, 23 normal pregnant women and 9 patients with twin pregnancies without preeclampsia at 28–32 weeks’ gestation were calculated using flow cytometry. In normal pregnant women, the percentage of Th1 cells and Th1:Th2 ratios were significantly lower than those in nonpregnant women. In twin pregnancies, the percentage of Th1 cells and the Th1:Th2 ratios were significantly lower than those in nonpregnancies. In twin pregnancies; in addition, the percentage of Th1 cells was significantly lower than that in singleton pregnancies. Our findings show a markedly predominant Th2 immunity in twin pregnancies.