A simple and sensitive radioimmunoassay for pregnancy-specific beta1-glycoprotein.

A simple, sensitive and relatively rapid radioimmunoassay for pregnancy-specific beta1-glycoprotein (PSbetaG) is described. The concentrations of PSbetaG in plasma from cord blood and in amniotic fluid were approximately 0-1% and 1-0% respectively of the maternal plasma levels. The amniotic fluid PSbetaG levels in pregnancies associated with an anencephalic fetus were not significantly different from normal levels.