[Pregnancy determination by the detection of early pregnancy associated protein].

First results of the immunoelectrophoretic detection of an early pregnancy associated protein (EPAP) are reported. For this a rabbit antiserum was produced against a serum fraction, which had early pregnancy factor activity, and used for rocket immunoelectrophoresis. By this method 95.3 per cent of 64 sera from patients with intact pregnancies were classified to be pregnant. There was found a positive correlation (r = 0.05; p less than 0.01) between the concentration of EPAP and the period of gestation (4th to 14th gestational week). However, the EPAP antiserum also reacted with serum proteins from probands using hormonal contraception. Further characterization and purification of the EPAP will help to produce an antiserum with higher specificity and therefore it will be possible to make a more reproducible early pregnancy test.