Embryo freezing is a procedure that allows the preservation of embryos due to situations that may affect the chance of pregnancy after embryo transfer or conditions that may affect the viability of embryos before transfer. Embryos are stored in special containers at -196°C in liquid nitrogen and are thawed in a special culture medium before the transfer procedure. The legal storage period for frozen embryos in our country is limited to 5 years. Advanced freezing and thawing techniques have significantly increased embryo viability rates. Frozen embryo transfer (FET) is performed with the patient's natural menstrual cycle or medicated preparation process, providing a safe, effective, and economical option.
After the embryo transfer is performed, if there is a problem that may reduce the chance of pregnancy (detection of fluid accumulation in the tubes, intrauterine polyp, recent bleeding during transfer, inability to enter the cavity during transfer, etc.), all embryos can be frozen for later transfer.
Embryo freezing may also be recommended before cancer chemotherapy or radiotherapy.
Embryos can be frozen at all stages of development. The freezing process is carried out by storing the embryos in special containers with a protective liquid in liquid nitrogen at -196 degrees.
When thawing the frozen embryos, they are removed from the liquid nitrogen, thawed at room temperature, placed in a special culture medium, and transferred to an incubator (devices specially designed for embryos). Depending on the freezing stage, the transfer of embryos can be performed on the same day of thawing or within 1-2 days.
According to our country's laws, frozen embryos can be stored for a maximum of 5 years. With the permission of the couple, storage can continue after the fifth year, or the embryos can be destroyed.
Viability rates in a good freezing and thawing program are approximately 90-95%. With the recent technological advancements, these rates can even reach 95-99%.
The incidence of anomalies in babies born from thawed frozen embryos is not higher compared to others. In conclusion, frozen embryo procedures are safe and economical practices for patients.
In frozen embryo transfer, the main principle is to prepare the patient's endometrium (inner lining of the uterus) to reach an adequate thickness for the development and implantation of the embryo. This can be achieved by waiting for the patient's natural menstrual cycle or by using medications.
Based on the preference for natural menstrual cycles or medication, follicular monitoring and/or thickening of the endometrium are followed. Hormone levels in the blood and ultrasound can be monitored during this period. The frozen embryos are thawed with special techniques before transfer and then transferred.
Embryo freezing is a reliable and effective method to preserve the chance of pregnancy in the future and provides an alternative solution in medical conditions that may hinder embryo transfer. It can also be applied before conditions that could affect reproductive health, such as cancer treatment. The viability rates after thawing frozen embryos are high, and babies born from them do not pose an additional risk in terms of health. When planning an embryo transfer, frozen embryos can be safely transferred after preparing the endometrium adequately.