During IVF procedure, hormones are given to woman in order to stimulate her ovaries to retrieve more eggs in egg retrieval process. If you are the one considered IVF, might be you have questions about what will happen to the extra embryos after the procedure. The extra embryos of a fresh IVF cycle can be frozen. Most of the patients going through IVF have an additional number of embryos which they may choose to cryopreserve or freeze.
History of FET
The technique of cryopreservation or freezing the human embryos was first introduced during 1950s with the pregnancies achieved after frozen sperm insemination. In 1983, the first pregnancy achieved from frozen embryo transfer was registered and since then thousands of babies have been born from FET technique.
Method of Cryopreservation
The process of embryo cryopreservation of embryos is typically performed as a part of In Vitro Fertilization that normally includes ovarian stimulation, egg retrieval and embryo transfer.
Vitrification and SPF (Slow Programmable Freezing) are two main techniques used for cryopreservation. The process of cryopreservation is the storing of live cells at very low temperature. The extra eggs retrieved during IVF are traditionally treated with a solution known as cryoprotectant (helps in lowering the freezing point of these eggs) before being cryopreserved.
Slow Freezing: It is a controlled rate cryopreservation method where programmable machines slowly cool the eggs prior to being deep frozen in liquid nitrogen.
Vitrification: It is a new cryopreservation method that involves the quick freezing of eggs that has been treated with cryoprotectants.
Process of Frozen Embyro Transfer
The time period require for FET may vary from patient to patient, however generally three to four weeks are required to perform the procedure. The number of embryos transferred during the process depends on numerous factors including the embryos quality and the patient age and also the number of available embryos for thawing process. Individual embryos are thawed from a previous fresh IVF cycle and then transferred back into the uterus of woman.
FET is a highly reliable and proven options for couple wish to proceed with their own embryos in future IVF cycle. Since its introduction in the medical science, the technique is widely used in several fertility clinics. Once patient is ready to use frozen embryos, the embryos will be previously thawed to room temperature and patient will be monitored for optimal timing of implantation. During the process, doctor uses a thin needle pass through the cervix and directly transferred embryos to the uterus.
Advantages of FET
FET involves less complication than fresh IVF cycle. Less medications and easier than IVF, however similarly successful as IVF or provide the same success rate as well. But this doesn't mean, you don't required to take medications while using frozen embryos, some medications are still required to prepare the uterine lining for transferred embryos. Additionally the IVF cycle using frozen embryos cost significantly less than IVF cycle with fresh embryos.