A 32-year-old primipara woman developed intense contractions that last 55-60 seconds with an interval of 1-2 minutes between them. Objectively, the disengagement of the fetal head begins. The perineum protrudes excessively and has the height of 4 cm. The skin of the perineum is pale and tense. After a contraction stopped, a thin stream of blood appeared from the genital opening. Specify the further tactics of managing the delivery.