The relationship of placental protein 14 (PP14) in the mother and fetus to specific products of the human placenta

Levels of placental protein 14 (PP14), human placental lactogen (hPL) and unconjugated oestriol (E3) were measured in maternal peripheral and umbilical arterial and venous blood obtained from 65 normal pregnancies at term delivery. PP14 levels were one order of magnitude higher in the mother than in the fetus. Neither maternal nor fetal levels of PP14 were related to the birthweight of the fetus. There was a relationship between maternal and umbilical venous levels of PP14, which suggests that fetal PP14 is derived by transfer from the mother, or that there is an independent fetal source with a control mechanism similar to that of the mother. The findings are compatible with earlier observations to the effect that PP14, in contrast to products such as hPL and E3, is not specific to the trophoblast.