A serial study of pregnancy proteins in primigravidae.

The plasma concentrations from four 'pregnancy proteins' and three steroid hormones have been measured throughout pregnancy in 15 primigravidae. Two of the proteins, human placental lactogen (HPL) and pregnancy-specific beta1-glycoprotein (PSbetaG), are specific for pregnancy and correlate well with the stage of gestation. It is suggested that measurement of PSbetaG may be useful in assessing feto-placental wellbeing. Neither of the pregnancy-associated proteins, steriod-binding beta-globulin (SBbetaG) and pregnancy-associated alpha2-glycoprotein (alpha2-PAG), correlated with the length of gestation although, near term, plasma alpha2-PAG levels appeared to be related to fetal weight. In addition, no correlation has been demonstrated between placental or fetal weight and any of the pregnancy-specific proteins or steroid hormones studied.