Pregnancy-specific beta-1-glycoprotein levels in cholestasis of pregnancy.

Plasma concentrations of pregnancy specific beta-1-glycoprotein (PSBG) were measured by specific radioimmunoassay in 211 samples from 123 normal women during the third trimester of pregnancy and in 166 samples from 68 patients with cholestasis of pregnancy. At 37--38 weeks of gestation patients with cholestasis had significantly lower PSBG levels than the normal pregnant women (P less than 0.005), whereas the levels in patients in the cholestasis had not been significantly different from those for normal pregnant women before 37 weeks. At 37--38 weeks of gestation patients with cholestasis showed a slight correlation between placnetal weight and plasma PSBS levels (r = 0.362; P less than 0.05), whereas this was not found in patients with normal pregnancy. No correlation was found between infant weight or length at birth and the PSBG concentrations in either group, and no difference was noted in PSBG concentrations between cases with and without fetal distress.