[Clinical significance of early pregnancy factor].

We studied the clinical significance of Early Pregnancy Factor (EPF), which was detected at a very early stage after fertilization in maternal serum, using a new stable assay system. The results obtained were as follows: EPF was useful for cyesiognosis at the earliest stage, as EPF was detected earlier than beta-hCG. Therefore the detection of EPF makes it possible to supply the first information concerning pregnancy. EPF was also useful in judging the potential for fertilization of gametes, especially spermatozoon, and other various factors. Differentiation between obstruction of fertilization and that of implantation was made possibly by measuring EPF. A high incidence of embryo loss was suggested. And we suggested the importance of the serum progesterone level in the preimplantation period as one of the many factors involved in embryo loss. EPF was also able to contribute to the prognostic diagnosis of abortion in early pregnancy, for it was a very sensitive marker of a viable embryo. These findings showed that EPF supplied new and very useful information as a marker of fertilization and a viable embryo, and it possessed clinical significance in the treatment of sterility.