[Alterations in the proteins found in the amniotic fluid in the course of normal pregnancy. A study carried out by immunoprecipitation tests on the amniotic fluid (author's transl)].

A fluonephelometric technique was used to study the proteins in amniotic fluid. 113 samples taken between the 8th and the 44th week of amenorrhoea from pregnancies without any fetal abnormality were tested. The levels of 8 protein fractions were estimated: albumen, IgG, IgA, alpha 1 antitrypsin, transferrin, orosomucoid, alpha 2 macro-globulin and IgM. 6 of these fractions could be estimated in almost every sample of amniotic fluid, but alpha 2 macroglobulines and IgM could only be found in a few cases. Furthermore, the fractions of the proteins most clearly shown appeared in a parallel way more or less as the total levels of proteins as estimated by Lowry's method.