[Biochemical and coagulation-physiology examinations before and after amniocentesis in early pregnancy].

In 46 women the alpha1-fetoprotein content, the soluble fibrin monomer complexes (LFMK), and the coagulation status were determined in the maternal serum at the beginning of the second trimester before and after amniocentesis. Increases of AFP by more than 100% of the original level pointed to fetomaternal microtransfusion, the quantity of which was calculated by means of a formula. Overall coagulation tests did not show any change after the puncture. A moderate LFMK increase was seen (p less than 0.05), which, however, was not clearly correlated with the AFP increase.