Cryopreservation of Embryos
Embryo cryopreservation is another important part of successful ART programs. Cryopreservation affords patients several advantages. Couples can cryopreserve embryos in excess of the ones that are usually transferred during an ART cycle. These embryos provide a second or even third opportunity for pregnancy without undergoing another ovarian stimulation and retrieval.
Those embryos that meet developmental criteria for appearance and rate of growth can be frozen at any of several stages in their development. The freezing process is computer controlled and employs special solutions to protect the fertilized eggs from damage. Frozen embryos are stored at -196°C or approximately- 400°F (below zero). Prior to ART you and your partner must sign a consent form indicating what we should do with any additional embryos. Current choices are disposal or cryopreservation for future use. Some programs offer the option of donating embryos for research or to other infertile couples. Policies on cryopreservation may vary from center to center.
As with cryopreserved semen, many embryos do not survive cryopreservation and thawing. Those that do survive may function less well than do fresh embryos; that is, they may implant and produce ongoing pregnancies at a somewhat lower rate than fresh embryos. Nationally in 2002, about 24% of transfers of frozen embryos resulted in the live birth of at least one infant.
We will usually transfer up to four embryos during this procedure. Embryos can be transferred successfully during an artificial cycle in which you take Lupron, estrogen, and progesterone.