Cryopreservation of Embryos, Sperm, and Oocytes

Egg, Sperm, & Embryo Freezing

Cryopreservation makes the use of liquid nitrogen for egg freezing, sperm, or embryos to -320 degrees Fahrenheit. The lab at the fertility clinic uses cryoprotective agents to prevent damage to the cells during the process. The cells can be frozen and stored for indefinite periods of time, for future use. 

At the time of freezing, all biological activity is suspended until the cells are thawed. When the eggs, sperm or embryos are needed, they are thawed and fertilised. Sperm may be used for intrauterine insemination (IUI) or in vitro fertilisation (IVF) procedures. Eggs and embryos will be used during procedures associated with IVF.

Factors

One of the things that a patient needs to keep in mind is that the patient needs to give her consent and permission for freezing the sperms, eggs, or embryos. You will be given a consent form that needs to be signed. 

The paperwork will have the below details that you need to discuss with the fertility doctor and your spouse:

• How many embryos/eggs/sperm will be frozen
• How long they’ll be stored (often 10 years)
• What happens when the storage time expires
• What happens if you die or become too ill to make decisions before the storage period is over
• What the embryos/eggs/sperm are allowed to be used for (for example, only your fertility treatments or if they can be donated to research or to another infertile couple)
• Your fertility doctor can also help you decide during which embryonic stage it’s best to freeze one or more embryos.

Stages of Cryopreservation

• Cleavage stage: When the single cell has multiplied to between four and eight cells after about 72 hours.
• Blastocyst stage: When the single cell has multiplied to between 200 to 300 cells after five to seven days.

Benefits of Cryopreservation

Cryopreservation can benefit many couples, especially in cases and circumstances when they are having medical complications or lifestyle. 

Some ways in which cryopreservation can prove to be beneficial are as follows:

• Ageing: Some couples get married quite late and then don’t wish to have a child immediately. Cryopreservation helps them buy time and prepare to have a baby whenever they wish to.
• Gender transition: Cryopreservation is a very viable and safe option for individuals and couples who are from the LGBTQ community and wish to start a family or have a child of their own. It is also a feasible option for women who are about to undergo gender transition.
• Infertility issues: For couples having infertility, cryopreservation can be a way to preserve blastocysts and embryos for IUI or IVF treatment.
• Single mothers: Women who are widowed at an early age or who are single mothers can opt for cryopreservation to preserve their eggs. They can later choose a donor sperm to have a baby.
• Social/lifestyle reasons: Individuals who may want to pursue higher education or who cannot have a baby soon due to career and lifestyle reasons can opt for cryopreservation.
• Cancer treatments: Chemotherapy or radiation treatment may damage fertility, and, in such cases, an individual may opt for cryopreservation before going for the cancer treatment.

Cryopreservation Of Oocytes

If a woman decides to go ahead with egg freezing, she must take hormonal medications daily for a few days to stimulate her ovaries to produce more eggs than normal. The medication will be prescribed by a fertility doctor. Once the eggs are determined as mature by the doctor, they are removed from the ovarian follicles and frozen by embryologists in the laboratory. Embryologists most often use vitrification to prepare the oocytes for storage. The oocytes may be stored in liquid nitrogen storage tanks at a fertility clinic until needed by the woman or couple for IVF treatments.

Cryopreservation Of Sperm

If a man decides to preserve his sperm, he can provide a sperm sample for cryopreservation. In some cases, surgical sperm extraction may be done if no sperm are present in the semen, or the man cannot ejaculate. During surgical sperm extraction the sperm are removed directly from the testicle. The sperm sample is then frozen and stored at a fertility clinic or sperm bank until ready to be used for intrauterine insemination (IUI) or IVF.

Cryopreservation Of Embryo

To preserve embryos, eggs are collected from the woman. In the IVF process, the eggs are then fertilised with the partner’s sperm in a lab. The resulting embryos are cultured for a few days, allowing the cell division process to reach optimal conditions before the embryos are frozen and stored at a fertility clinic or cryopreservation bank until they are to be transferred into the female’s uterus later.

What is the Cost of Cryopreservation

Cryopreservation means freezing and storing eggs for using later and it can be done for oocytes, sperm, and embryos. Cryopreservation is a viable option for those about to undergo cancer treatment, couples wanting a second child after IVF treatment or those who have lifestyle constraints.