RESUMEN
An inhibitory serum factor of mixed lymphocyte culture (MLC) has been associated with successful pregnancy after lymphocyte transfusion in women with unexplained recurrent spontaneous abortions (RSA). Objective: Investigate whether the inhibitory serum factor of MLC is essential for a successful pregnancy. Method: Sera from 33 healthy pregnant women and from 40 women with RSA were assessed by a one-way MLC in which the woman's lymphocytes were stimulated with her partner's lymphocytes or with third party lymphocytes. Results: An inhibitory serum effect (inhibition >50 percent as compared to normal serum) was detected in 45 percent of the pregnant women who had at least 1 previous parity, in 8 percent of the primigravidea, in 29 percent of those with one abortion and in 58 percent of those with more than one abortion. Conclusion: MLC inhibitory serum factor does not seem to be an essential factor for pregnancy development. Therefore, it should not be considered as a parameter for the assessment of RSA patients.