Fresh or Frozen Embryo Selection in Embryo Transfer: Live Birth Rates and Obstetric and Fetal/Neonatal Results

Abstract

: Assisted reproductive techniques used in the treatment of infertility have been promising methods for infertile individuals. Embryo selection and embryo transfer are an important part of assisting reproductive techniques. The selection of the embryo to be transferred is important for the implantation and clinical pregnancy success. In addition, whether to use a fresh embryo or frozen embryo for embryo transfer is a controversial issue. While the fresh embryo transfer technique is widely used, the frozen embryo transfer technique has become widespread. The main factor in choosing the method of freezing the embryos is to avoid the negative effects of controlled ovarian hyperstimulation on endometrial receptivity. Therefore, it is thought that the use of frozen embryos can improve pregnancy outcomes and reduce the risk of developing obstetric and perinatal problems. However, in the embryo freezing technique, there are problems such as the risk of developing degeneration in the embryo during freezing or thawing process and postponing the transfer. In addition, adverse conditions have been reported such as an increased risk of developing hypertensive disorders in the mother and macrosomia in the baby.