[Embryotoxic factors and recurrent spontaneous abortions]

About 30% of recurrent spontaneous abortions remain unexplained by traditional or biological anomalies. The purpose of this work was to investigate embryotoxic factors produced by trophoblast stimulated lymphocytes from women with unexplained recurrent spontaneous abortion. The samples from 36 women with recurrent abortion before and during the next pregnancy and from 7 women with normal pregnancies and no history of spontaneous abortion have been tested. The lymphocytes were stimulated with trophoblastic extracts. The supernatants of the stimulated lymphocytes were tested in a 4-cell mouse embryo culture. The secretion of embryotoxic factor was determined if the number of life blastocysts was less than 50% of control values after 4 days. The lymphocytes from 59% women with 3 or more recurrent abortion produced the embryotoxic factor, this factor may be useful in predicting pregnancy outcome in women with a history of unexplained recurrent miscarriage. The embryotoxic factor might be a new cause of recurrent abortion and a predictive factor.