Embryo transfer is the final "stage" of the IVF procedure. Once embryos have been transferred to the patient's uterus, all she can do is wait and hope that at least one of them will implant in her uterine lining and grow into a baby. Transfer takes place after the eggs have been retrieved from her ovaries and fertilized using sperm from her partner or from a donor in the laboratory.
Preparing The Uterus
To increase the chances of successful embryo implantation, a woman may need some help in the form of drugs to encourage her uterine lining, or endometrium, to thicken and get ready to receive an embryo. Normally, this thickening of the uterus occurs during the ovulation-inducing process. The fertility doctors at the woman's clinic will monitor the progress of her uterine lining using ultrasound scans. If it seems to be too thin, they'll prescribe her some estrogen and progesterone - these are hormones that encourage growth of the endometrium.
After fertilization takes place, the embryos are usually left for 2 to 3 days to develop before transfer. Embryos have usually divided to form between 2 to 8 cells before they are transferred to the uterus. Sometimes they can be left for a few more days to develop more and grow stronger - this is called a blastocyst transfer.
Embryo transfer is usually painless although some women do report some mild cramping. If you're someone who usually feels discomfort during a Pap smear test, you may want to request a mild sedative before the procedure, because just like a Pap smear test, embryo transfer requires the opening up of the cervix using a speculum.
Transfer is carried out in conjunction with an abdominal ultrasound exam. The doctor performing the procedure takes a transfer catheter loaded with the embryos and inserts it through the vagina and cervix until it reaches the top or "fundus" of the uterus. He simultaneously watches what he's doing on the ultrasound screen. He then expels the embryos from the catheter and withdraws it. The hope is that one of the embryos will implant and the patient will become pregnant.
Number Of Embryos
It is only ethical that fertility doctors limit the number of embryos transferred to the uterus, because if more than one implants and a multiple pregnancy is conceived, both mother and babies will be at risk. Most doctors will therefore transfer no more than 3 embryos at one time. The older the patient, the more embryos are usually transferred.
If you are uncomfortable with the idea of "wasting" fertilized embryos, or you want to preserve embryos for future IVF cycles, you might want to consider embryo freezing.
It doesn't take long to recover from the transfer procedure. There is currently no medical evidence to suggest that either bed rest or returning to your usual activities will increase the chances of a successful pregnancy. However, some women prefer to take some time to rest and gather their thoughts, which is completely understandable.