Chemical abortion in patients with recurrent fetal loss.

The incidence of chemical, or pre-clinical, abortion was determined in 10 women on 3 occasions after Day 8 after ovulation with a highly sensitive enzyme immunoassay for beta hCG carboxyterminal peptide. Chemical abortion is defined as occurrence of 0.25 mIU hCG/ml on 3 occasions after Day 8 of ovulation on the basal body temperature chart, but menses occurs on schedule. The subjects were selected from a group of 1120 women with history of repeated spontaneous abortion who had been evaluated at the Keio University Hospital between 1984-1990. These women had an average of 3.22 pregnancies, of which on average 2.9 had ended spontaneously. In 4 of these 10 women hCG was 0.25 mIU/ml in first morning urine, but their menses arrived on schedule, and they had no clinical signs of pregnancy. Levels of hCG were 0.25, or 0.25 mIU/ml less than 3 times in the other 6 women. The normal level of hCG in nonpregnant women was reported to be 0.16 mIU/ml. This is the 1st report of documented chemical abortion in a habitually aborting population.