Summary. Pregnancy-associated plasma protein-A (PAPP-A) and Schwangerschaftsprotein 1 (SP1) levels were measured in single serum samples from 60 patients admitted with vaginal bleeding in the first 14 weeks of pregnancy. When based on ultrasound diagnoses the prediction of non-viability (the predictive value) was 97% for SP1 and 84% for PAPP-A. Whereas the prediction of viability (above –2SD of the normal range) with SP1 was 88% the value with PAPP-A was only 57%; the poorer result obtained with PAPP-A probably reflects its longer half-life. Pregnancy outcome is not related to the duration of bleeding.