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

Abstract

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.