Many couples working with Dr Douglas will have successful IVF cycles, which will result in remaining embryos to freeze or cryopreserve for future cycles. These cycles, called Frozen Embryo Cycles, or FETs, allow couples the chance to conceive multiple children from one IVF cycle. FETs help control the cost of multiple IVF cycles and have an excellent chance for pregnancy. Presbyterian ARTS and Dr. Douglas have received national recognition for frozen cycle pregnancy rates. For couples that elect to freeze embryos, the cryopreservation process continues outside the woman’s body in the Presbyterian ARTs laboratory. Embryos continue to grow until day 5 or 6, and at that point, the embryologists review them for the potential capability to survive freezing and result in a future pregnancy. Embryos that meet the requirements are then prepared for freezing and storage. One of the freezing techniques used by Presbyterian ARTS is vitrification, or “quick freeze.” With vitrification, the embryo is exposed to high concentrations of cryoprotectant for a very short period of time, after which it is plunged directly into liquid nitrogen.

IVF Treatment Information IVF Plano Success Rates Growth of the Egg Retrieval of the Egg Sperm and Fertilization Growth of the Embryo Embryo Transfer and Support Preimplantation Genetic Screening (PGD/PGS) Embryo Storage

The cryoprotectant serves to remove water from the cells and lower the freezing point of the embryo’s tissue to allow for a very rapid freeze and significant decreases the amount of ice crystals formed inside the embryo. Ice crystal formation inside the cells can damage the embryo and decrease embryo’s chances of survival. The cryoprotectant solution may also serve to protect the membranes of the cells in the embryo during the freezing process.

All frozen embryos are stored in liquid nitrogen, which has a temperature of -196C (-321F). Storage at this extremely cold temperature essentially halts the growth and internal processes of the embryo, allowing preservation and survival or an indefinite period of time.

When the embryos are needed for a frozen embryo transfer they are thawed, assessed for survival and placed in culture media for incubation. This incubation period allows the embryo to complete its recovery and begin to resume its metabolism and growth process.

Once growth process begins again, Dr Douglas will return the embryos to your uterus in a transfer process similar to IVF transfer.

Read more about Assisted Reproductive Technologies - an ASRM Sheet