CD27 and abortion: Among the B cell populations identified as being significantly associated with abortion in this study (p < 0.05), Unsw mem %B cell, PB/PC %B cell, IgD+ CD24+ %B cell and Naive-mature B cell %lymphocyte were found to increase the risk of abortion (OR > 1), whereas CD20 on IgD- CD27- was associated with a decreased risk of abortion (OR < 1).