A parturient woman is 30 years old, Stage 1 of the labor is ongoing. The fetus is in the cephalic presentation. Auscultation of the fetal heart sounds detects bradycardia. Evaluation of cardiotocogram yielded the following data: decrease of basal heart rate down to 90/min., variability – monotonous (2 and less): late decelerations with amplitude of 50/min. Make the diagnosis and choose the obstetrical tactics necessary in this case: