To evaluate the autonomic nervous system (ANS), a Neuron spectrum diagnostic system was used to examine 40 pregnant women by a cardiointervalography technique (in the right lateral position for 5 min) 1-5 days before labor, in the latent phase of its first stage, and within the first 1-5 days postpartum. In uncomplicated birth activity to the latent phase of the first labor period, the activity of the sympathetic part (SP) of the ANS was shown to increase as compared to that before labor, but to fail to achieve the level characteristic of the second and third trimesters of pregnancy and, in the postpartum period, it gradually restored to the level observed in non-pregnant women. The women whose delivery was complicated by powerless labor (PL) showed a low activity of the sympathetic part of the ANS, low blood pressure, and low maturity of the cervix uteri just before birth. The activity of SP of ANS failed to rise (and even declined) in the latent phase of the first stage of labor; on the contrary, it increased during the postpartum period. By and large, in these women, the activity of SP was lower before labor and in the latent phase of its first stage than in those with uncomplicated labor, and on the contrary, it is higher in the postpartum period. This all allows one to consider PL as a manifestation of autonomic dysfunction, in which the action of the parasympathetic part of ANS predominates over its SP, which eventually retarded the optimal relaxation of cervical myocytes and the opening the cervix uteri. The indicators that can be used in clinical settings to make up a PL risk group are proposed.