With increasing hypoxia and acidosis the four index parameters do show a complex pattern which is characterized by tachycardia, increase of EXT and opening of the OA. A loss of EXT and a reduction of OA seems to be the result of already severe acidosis (pH, UA < 7.000). Using the four parameters of basal FHR alone, there is no possibility to evaluate fetal jeopardization. Numerical combination (e. g., multiplication) of some index parameters ameliorates their prognostic power and should be used in future online scoring procedures.