Origin of Proteins in Amniotic Fluid

Abstract

THE origin of the proteins in amniotic fluid is not known with any certainty. Previous evidence, obtained from investigations with electrophoretic techniques^1,2 and labelled proteins³, suggests that they are obtained from the maternal circulation by filtration through the foetal membranes. The fact that human placental lactogen (HPL) is found in appreciable amounts in normal amniotic fluid and maternal serum, while it cannot be demonstrated in cord blood⁴, raises the question of whether this protein hormone originates from its maternal or the foetal circulation. This question is important if the endocrine activity of the protein is to be explained.