Detection of fetal wastage.

Production of the pregnancy-specific protein early pregnancy factor (EPF) was monitored by the rosette inhibition test in a group of 13 nulliparous women. EPF could be detected in serum within 48 hours of fertilization; of 28 cycles in which intercourse took place at the time of ovulation, EPF was detected in 18. However, EPF production continued for more than 14 days in only four cases. Successful pregnancy was maintained in two of these while in the other two, disappearance of EPF preceded miscarriage. In the remaining 14 cases, EPF disappeared from the serum before the onset of menstruation. A high incidence of early embryonic loss is suggested.