Embryo transfer is the last stage of IVF. Embryos may be transferred into the uterine cavity 2- 3 days after oocyte retrieval, when they have reached the 4- 8 cell stage. In certain cases embryos may be transferred on day 5-6 after oocyte retrieval, at the blastocyst stage.
In our center early-cleavage embryos are also transferred into the uterine cavity during the first day after oocyte retrieval ,and good pregnancy results have been obtained.
Embryos are placed through the cervical canal into the uterine cavity using a specially designed flexible catheter. Ultrasound guidance is used to properly place the embryos in the uterus.
This procedure usually requires no anesthesia. The patient rests for an hour at the center and then returns home, avoids intense physical stress for the next 2-3 days and finally returns to her normal activities.
Two to four embryos are transferred, depending on the age of the woman, infertility factors, previous obstetric history, etc.
Good quality embryos that are not transferred, are cryopreserved (frozen), stored and thawed at a later date for use in future menstrual cycles.
Proper method (correct use of embryo transfer catheter, cervical preparation, embryo handling), embryo quality and endometrial receptivity , are the major factors affecting pregnancy rates.