In a woman in labor weighing 70 kg 40 minutes after birth, a large fetus (4500 g) appeared significant bloody discharge from the genital tract. Bladder emptying was performed and external uterine massage; after which the uterus contracted, but for 5 minutes bleeding recovered. After the introduction of uterotopics, manual examination of the uterine cavity blood loss was 1200 ml. What should be the next tactic?