What is Cryopreservation?

Freezing sperm, embryos, or eggs for future use in completing an in vitro fertilization (IVF) or intrauterine insemination (IUI) procedure is called cryopreservation. The special environment where frozen eggs, embryos or sperm are placed is called a Cryochamber. Technologies involved in cryopreservation of embryos are slow-programmable freezing (SPF) or vitrification. However, vitrification is rapidly becoming the technology of choice for freezing eggs and embryos. Research results indicate that vitrification is superior to SPF when it comes to implantation and survival rates. In addition, vitrification may reduce a minimal chance of DNA damage than the slower, SPF method of cryopreservation.

Advantages to Vitrification

Cryochambers employing the cryopreservation technique of vitrification freeze eggs so rapidly that potentially harmful ice crystals cannot form. The process of vitrification involves an egg being placed in a liquid bath of cryoprotectants and sucrose that draws water out of the egg. The egg is then instantly frozen in a bath of liquid nitrogen. The egg remains in a cryochamber until the woman who preserved her egg is ready for an IVF or IUI procedure. Unfreezing the egg involves rapid warming of the egg and thoroughly washing off cryoprotectants. Vitrification is also used to freeze embryos.

Better Chance for Pregnancy

Freezing embryos also provides additional opportunities to attempt pregnancy. If a woman stores her embryos in a cryochamber while going through a cycle transfer, this allows her to try again if the cycle is unsuccessful without experiencing another egg retrieval or ovarian stimulation procedure. In other words, a woman’s cumulative rate of achieving pregnancy actually increases from one in vitro fertilization cycle.


Frozen embryo transfer cycles may also be scheduled at more convenient times. Once a woman is scheduled for a FET, she can begin taking oral estrogen to prepare the uterine lining for the transfer. Injections of progesterone are also given to help support the body during pregnancy.

Genetic Testing

When you freeze your embryos, you can opt for a preimplantation genetic diagnosis that evaluates the embryo’s chromosomal material. A PGD tells your fertility doctor how many chromosomes an embryo has. The normal number of chromosomes is 46. This means only a chromosomally normal embryo will be transferred at the appropriate time. PGDs are especially useful for couples who know they could pass on a genetic disorder and for women over 35 who want to have a child.

Cancer Treatments

Women diagnosed with cancer who require chemotherapy or radiation therapy can freeze their embryos or eggs until after they have completed treatment. Cancer therapy may degrade the viability of eggs or destroy them altogether. Freezing them before beginning cancer treatment allows women to potentially achieve pregnancy after they have been successfully treated for cancer.

Why Do Men Freeze Their Sperm?

Freezing sperm involves a process similar to the process used to freeze eggs or embryos. Men may want to freeze sperm if they are undergoing cancer treatments, know they must have testicular or pelvic surgery or have a medical condition that makes it difficult to achieve an erection. Men in their 20s or 30s who want to wait to have children after establishing a career may choose to freeze healthy sperm before undergoing a vasectomy. Sperm can remain frozen for up to 10 years without damaging viability.

Viera Fertility Clinic Offers Cryopreservation for Eggs and Embryos

We employ extra precautions, inspection safeguards, state-of-the-art monitoring systems, and backup liquid nitrogen tanks for our cryochamber at our fertility clinic. We assure our patients that frozen eggs and embryos are continuously supervised and checked 24/7. This includes visual inspections of the cryochamber as well. Installation of remote monitoring systems provides our staff with instant notifications if even the slightest temperature changes are detected. In addition, Viera Fertility is proud to be able to report that no irregularities have been reported regarding cryochamber processes.

If you are interested in learning more about cryopreservation of eggs and embryos, please contact Viera Fertility Clinic today to schedule an appointment with our fertility physician.