A 25-year-old parturient woman is hospitalized with contractions that have been occurring for 12 hours already. The contractions last 25 seconds, while the intervals between them last 3-4-7 minutes. The contractions are irregular and sharply painful, with pain spreading upwards from the lower uterine segment. The baby is in the cephalic presentation, the head is pressed to the entrance into the lesser pelvis. Uterine hypertonus is observed Internal obstetric examination shows that the cervix is smoothed and the opening of the external orifice uterus is 3 cm. The amniotic sac is intact. Make the provisional diagnosis