A 28-year-old female patient complains of having hemorrhage from the genital tracts for 1 month. 6 months ago she had natural delivery and gave birth to a girl weighing 3100 g. Objectively: the uterus is enlarged to 9-10 weeks, mobile, painless, of heterogenous consistency. Examination reveals vaginal cyanosis, anaemia and body temperature rise up to 37,8°C. There is a significant increase in hCG concentration in the urine. What is your provisional diagnosis?