экстракорпоральное оплодотворение, замершая беременность, эмбрион высшего качества, поздний репродуктивный возраст, in vitro fertilization, missed abortion, best quality embryo, late reproductive age, Medicine

The study was conducted during the years 2013--2014 by the assisted reproductive technology (ART) department of the Moscow Regional Perinatal Center in Balashikha. We analyzed 384 IVF and ET cases using clinical and embryological criteria. It was found that the outcome of induced pregnancy is associated with such factors as patient age, body mass index, polycystic ovary syndrome, hyperandrogenism, congenital thrombophilia, endometrial pathology, miscarriage history, total dose of HT per COS cycle, number of best quality embryos in ovarian cohort, level of serum hCG on day 14 after embryo transfer. "Best quality embryo in ovarian cohort" factor is of great interest due to high reliability and few studies in this area. Quality distribution of embryos does not occur randomly or as part of an isolated in vitro process; it follows a certain pattern that directly affects the outcome of pregnancy.