Lymphocyte subsets in habitual abortion.

Lymphocyte subpopulations were characterized by means of monoclonal antibodies in 25 women with habitual abortion and 21 multiparous normal women. Compared to nonpregnant women (N = 8), pregnant normal women were associated with significantly lower helper-to-suppressor ratios (1.71 +/- 0.41 versus 2.37 +/- 0.66). In contrast in pregnant women with habitual abortion (N = 13) the ratio remained high (2.32 +/- 0.73). Failure to increase the number of suppressors and a significant rise in helpers caused this increased ratio. We discuss the possible mechanisms and etiological importance of this finding in habitual abortion.