Embryo transfer is a procedure that involves transferring embryos from an in vitro fertilization procedure. Generally, embryos are transferred two to three days after retrieval. This allows a doctor to observe the growth of the embryos. Historically, embryo transfers were performed on the day of retrieval, which prevented the doctor from observing the development of the embryo. However, advances in technology have allowed doctors to monitor the development of the embryos during the transfer process. These advances include the development of blastocyst culture, which helps to separate the good embryos from the bad ones. These embryos are known as blasts, and the transfer of blasts is associated with higher rates of pregnancy.
During the procedure, a catheter containing embryos is inserted into the uterus under ultrasound guidance. Once inside, the embryos are deposited at a distance of 1.5 cm from the fundus of the uterus. After the procedure, the patient is required to remain seated for about 20 minutes. A follow-up appointment will help the doctor determine whether the embryo has implanted successfully.
Embryo transfer is a safe and effective procedure. However, there are risks involved. One of the most serious risks is multiple pregnancy. Multiple embryos can attach to the uterus, increasing the chances of a stillbirth or a child with special needs. In addition, multiple pregnancies are more common with IVF than in natural conception.