Radioimmunoassay of SP1 (pregnancy-specific beta1-glycoprotein) in maternal blood and in amniotic fluid normal and pathologic pregnancies.

During the last years there has been increasing interest in the investigation of biochemical parameters which in addition to placental steroids and peptide hormones might be indicators of placental function and fetal well-being. In this paper we present data on the pregnancy-specific si -glycoprotein S?! and tiy to evaluate its clinical significance. SPj was isolated and characterized by BOHN [l, 2]. TATARINOV reported on comparative immunodiffusion investigations which showed identity of his pregnancy specific s-globulin [20, 21] andof PAPP-C of LIN et al. [9] with pregnancy-specific si -glycoprotein (SPi). SPj was characterized as a sl -glycoprotein with a carbohydrate content of 29% and a molecular weight of 90000-110000 [3, 9]. Recently the occurrence of a high molecular weight variant was proposed [25]. The protein is synthesized in the syncytiotrophoblast of the placenta [8, 18] and secreted into the maternal blood in increasing concentrations as pregnancy proceeds [5,6,16,21,29, 31]. Its detection is possible as early as 18 days