IVF embryo transfer refers to a step in the process of in vitro fertilization (IVF) whereby one or several embryos are placed into the uterus of the female with the intent to establish a pregnancy. The objective of this procedure is to facilitate conception following fertilization from the in vitro fertilization procedure.
Embryos are generally transferred back to the woman’s uterus at the two – eight cell stage, which occurs 48 – 72 hours after the retrieval. There are minimal risks with the embryo transfer procedure. The procedure is usually painless, although some women experience mild cramping. The procedure usually takes between 10 and 20 minutes under ultrasound guidance to ensure proper placement of the embryos. Transferring more embryos increases the chances of getting pregnant, and also increases the risk of a multiple pregnancy.
The success rates of the frozen embryo transfer depends upon a variety of factors, particularly maternal age and the number of embryos transferred. It is important to know that not all embryos will survive the freezing and thawing process though. About 90% of embryos survive cryopreservation, and this can sometimes impact the success rates of frozen embryo transfer. This makes it important to freeze and thaw a number of embryos when performing the frozen embryo transfer procedure.