Objective: To determine whether the production of embryotoxic factors in early pregnancy is predictive of pregnancy outcome in women with a history of two or more unexplained recurrent abortions.
Methods: Between July 1987 and June 1991, 450 nonpregnant women were evaluated for recurrent abortion. Embryotoxic factors were found in 328 of 346 women with an otherwise unexplained etiology. These women were given progesterone immunosuppressive therapy in a subsequent conception cycle, and embryotoxic factors were measured at 5 weeks' gestation.
Results: Data on embryotoxic factors and pregnancy outcome were available for 141 of 208 reported subsequent pregnancies. Of women still positive for embryotoxic factors, 40 had a repeat first-trimester spontaneous abortion whereas 16 delivered a viable infant; of women who no longer produced embryotoxic factors, only 11 had a repeat first-trimester abortion and 74 delivered a viable infant.
Conclusions: The embryotoxic factor assay may be useful in predicting pregnancy outcome in women with a history of unexplained recurrent abortion. Further work is needed to evaluate the effectiveness of immunosuppression for this condition.