New applications for the assay of placental proteins

Diagnosis of early pregnancy by enzyme immunoassay of Schwangerschafts-protein 1

Serum Schwangerschafts-protein 1 (SP1) and beta subunit of human chorionic gonadotropin (beta-hCG) were measured by enzyme immunoassay and radioimmunoassay, respectively, in the follicular phase and luteal phase of 50 human menopausal gonadotropin treatment cycles. SP1 could be detected in 63% of blood samples taken in the follicular phase up to the level of 1.56 micrograms/l. Using a cutoff level of 2 micrograms/l, SP1 could be used to diagnose pregnancy 16 to 25 days after the ovulating dose of hCG. The serum SP1 level is not affected by hCG injections and it can be used for diagnosis of pregnancy even when hCG has been given recently. SP1 also may be used as a prognostic indicator of the outcome of the pregnancy.

Early conceptual loss in subfertile patients

The incidence of early conceptual loss was studied in 27 subfertile women by measuring their serum and urine hCG levels in the luteal phase. Eleven patients eventually had clinically confirmed pregnancies, nine of whom had had significant hCG elevations in previous menstrual cycles. In the remaining 16 patients, who have so far failed to achieve a clinical pregnancy, only three had had elevated hCG results. Thus 'apparent' early conceptual loss in non-pregnancy cycles was found to be more often associated with the fertile group of patients.