Diagnosis of early pregnancy by assay of placental proteins.

The plasma concentrations of Schwangerschaftsprotein 1 (SP1) and human chorionic gonadotrophin (hCG) were measured in 22 women before and after conception. In these pregnancies ovulation occurred spontaneously in seven subjects, or followed treatment with either clomiphene citrate (6 subjects), or human menopausal gonadotrophin (hMG) and hCG (6 subjects). The remaining three patients became pregnant after artificial insemination with donor semen. Seventeen of these pregnancies were normal and five were abnormal (3 abortions, 1 ectopic and 1 twin). SP1 could be detected 6-14 days after ovulation in all these patients. In contrast 40 non-pregnant women gave a negative test for SP1.