A 30 y.o. woman is in her second labor that has been lasting for 14 hours. Fetal heartbeats are muffled, arrhythmic, 100/min. Vaginal examination results: cervical dilatation is complete, fetal head is close to the exit of small pelvis. Sagittal suture has the direct diameter, small crown is close to the pubis. What is the further tactics of labor management?