The embryo transfer is the last step in the in vitro fertilization process. It is also the most crucial and delicate procedure. The success of in vitro fertilization is dependent on the precise placement of the embryos near the middle of the endometrial cavity. But first, there are several steps prior to this placement that have to happen before the embryo transfer can occur.
The Basics of In Vitro Fertilization
Couples who are seeking to conceive through in vitro fertilization will have a number of procedures to complete. Women will be given medication to help prepare the eggs for retrieval, and the men will be asked to provide a semen sample which will then be “washed” to isolate viable, healthy and motile sperm. When the eggs are mature, egg aspiration is performed and the eggs are mixed with the sperm approximately four hours after aspiration. They are checked for fertilization the next morning.
The Next Step of In Vitro Fertilization
The next morning, the eggs and sperm are checked for fertilization. Fertilized eggs, at this point called embryos, are cultured in the laboratory for 1-5 days before transfer. Typically, 1-2 embryos are transferred, but this depends on discussions between the couple and their in vitro fertilization specialist. Usually, the older the woman, the more embryos are transferred because as a woman ages, the chances of viable embryos implanting decreases.
This part of the in vitro fertilization process is relatively painless and no more bother than having a Pap smear, therefore no sedation or other drugs are involved. The woman will be asked to appear with a full bladder, as this makes it easier to visualize the uterus for placement of the embryo. The embryo transfer catheter is then loaded with the proper number of embryos, and passed through the cervical opening into the uterus. Everything is tracked by ultrasound.
What Happens Immediately Following Embryo Transfer?
The patient will be asked to lie on her back for generally an hour after the embryos have been placed. Activity should be limited to the couch or a recliner for the rest of the day. Regular activity can be resumed the next day, although it is advised to refrain from high impact activities including jogging, aerobics and “rough” sex until a positive pregnancy test is obtained.
Implantation of embryos typically takes place 1-5 days after in vitro fertilization. A blood test for pregnancy is recommended, as home pregnancy tests or urine pregnancy tests often give “false” negatives. This can be done 9-10 days after in vitro fertilization. The success rates for in vitro fertilization vary, but generally range between 45-60%.