Masson G M, Anthony F, Wilson M S
Br J Obstet Gynaecol. 1983 Feb;90(2):146-9. doi: 10.1111/j.1471-0528.1983.tb08899.x.
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.