[Determination of the mean pH of fetal blood during the pushing phase of labor].

The pH of the fetus and mother in the phase of pressing in 100 normal deliveries, which served as the control group, was analysed. An average decrease of the pH by 0.07 in both the fetus and the mother was recorded, starting from the full opening of the cervix until the termination of labour. This result is evaluated by the determination of the pH in 121 cases of disturbed pregnancies, singling out 9.9% of fetus in preacidosis and 11.6% of fetus in acidosis, which is significantly higher than in the control group. It is pointed out that the detection of acute fetal suffering in labour should not be limited to the time of opening only but that it should be carried out also in the phase of pressing.