Plasma levels of pregnancy-specific beta 1-glycoprotein in complicated pregnancies.

Maternal plasma levels of the trophoblast product, pregnancy-specific beta 1-glycoprotein (PS beta G), have been measured both in normal pregnancies and in pregnancies complicated by pre-eclampsia and/or fetal growth retardation. PS beta G levels correlate significantly with placental and fetal weight and fall below the normal range in about 60 per cent of all patients with fetal growth retardation. PS beta G measurements appear to give a considerably better indication of fetal size than measurements of either human placental lactogen (HPL) or plasma oestriol.