Why we should transfer frozen instead of fresh embryos: the translational rationale

摘要: Epidemiologic studies have shown an increased rate of adverse perinatal outcomes, including small for gestational age (SGA) births, in fresh in vitro fertilization (IVF) cycles compared with frozen embryo transfer cycles. This increase is not seen the donor oocyte population, suggesting that it peri-implantation environment created after superovulation responsible these changes. During a IVF cycle, multiple corpora lutea secrete high levels hormones and other factors can affect endometrium implanting embryo. In this review, we discuss both animal human data demonstrating has significant effects on Additionally, potential mechanisms gonadotropin stimulation implantation placental development are proposed. We think data, along growing body epidemiologic evidence, support proposal should be considered preferentially, particularly responders, as means to potentially decrease at least some outcomes associated IVF.