Cryopreservation: Preserving Fertility for the Future

What Is Cryopreservation?

Cryopreservation, also known as cryoconservation, is a specialized technique used to freeze and store reproductive cells and tissues at extremely low temperatures for future use. These biological materials—including eggs, embryos, sperm, ovarian tissue, and testicular tissue—are preserved in liquid nitrogen at -196°C, maintaining their quality and viability over time. Cryopreservation plays a key role in fertility treatments, providing options for individuals and couples to conceive later in life.

Egg Freezing (Oocyte Cryopreservation)

A woman's egg supply declines in quality and quantity after the age of 35, making egg freezing a valuable option for preserving fertility. Unfertilized eggs can be stored and later used to achieve pregnancy through IVF.

When Is Egg Freezing Recommended?

Women may choose elective egg freezing for various reasons, including:

Family history of early menopause, increasing the risk of premature ovarian failure.
Cancer diagnosis, where treatments such as chemotherapy, radiation, or surgery may damage the ovaries. Fertility preservation allows women to conceive after cancer treatment.
Medical conditions requiring ovarian removal, such as severe endometriosis or recurrent ovarian cysts.
Social egg freezing, for women who wish to delay pregnancy for personal reasons, such as career goals or waiting for the right partner.

How Does Egg Freezing Work?

Initial Consultation: The process begins with a fertility specialist consultation, where blood tests and an ultrasound assess ovarian reserve (egg supply).
Ovarian Stimulation: Fertility medication is administered for 8–12 days to encourage the ovaries to produce multiple mature eggs.
Egg Retrieval: Once the eggs are ready, they are collected in a minor procedure.
Vitrification (Rapid Freezing): The eggs are frozen using a fast-freezing method to protect them from damage.
Storage: The frozen eggs remain safely stored until the woman decides to use them for pregnancy.

Women can also opt for embryo freezing, where eggs are fertilized with sperm before storage.

Embryo Freezing (Embryo Cryopreservation)

During IVF or ICSI, multiple embryos are created. While the best-quality embryos are transferred to the uterus, additional embryos can be frozen for future use.

Benefits of Embryo Freezing:

Eliminates the need for repeated ovarian stimulation, allowing future pregnancy attempts without hormone injections or egg retrieval.
Higher chance of conception, as only high-quality embryos are frozen.
Fertility preservation for cancer patients, allowing them to attempt pregnancy after treatment.

How Does the Frozen Embryo Transfer (FET) Process Work?

A frozen embryo transfer cycle is simple and minimally invasive:

Endometrial Preparation: The woman’s uterus is prepared for implantation through natural cycle monitoring or hormone therapy.
Embryo Thawing: The frozen embryo is carefully warmed for transfer.
Embryo Transfer: The embryo is placed directly into the uterus.
Pregnancy Testing: A blood test after 10–14 days confirms if implantation was successful.

Are There Any Risks?

While embryo freezing is highly effective, approximately 70% of embryos survive thawing. The success rate depends on individual factors, but frozen embryos generally have a slightly lower implantation rate than fresh embryos.

Sperm Freezing (Sperm Cryopreservation)

Sperm freezing is an excellent option for men who wish to preserve their fertility due to medical treatments or personal reasons.

Who Can Benefit from Sperm Freezing?

Men with low sperm count, needing multiple samples for fertility treatments.
Patients undergoing chemotherapy, radiation, or surgery that may cause infertility.
Men preparing for a vasectomy who want the option to conceive later.
Donor sperm storage, allowing single women or same-sex couples to achieve pregnancy via IUI or IVF.

Sperm samples are frozen and stored safely for future fertility treatments.

Testicular Tissue Freezing

For men unable to produce sperm in their ejaculate, testicular tissue freezing (through TESE) allows sperm to be retrieved directly from the testes and stored for later use in ICSI treatments. This method is beneficial for men with non-obstructive azoospermia (lack of sperm in semen).

Ovarian Tissue Freezing

Ovarian tissue cryopreservation is an advanced fertility preservation technique where ovarian tissue is surgically removed, frozen, and later re-implanted to restore fertility. It is especially beneficial for:

Young women undergoing cancer treatments that may cause ovarian failure.
Patients with conditions requiring ovary removal, such as severe endometriosis.
Women who want an alternative to egg freezing, as ovarian tissue may still produce hormones naturally.

When Is Cryopreservation Useful?

Cryopreservation is a valuable option in the following situations:

As part of IVF treatments, where extra embryos are frozen for later use.
Before medical treatments, such as chemotherapy, radiation, or surgery, that may cause infertility.
For social freezing, where individuals wish to delay parenthood while preserving their fertility.

Take Control of Your Fertility

Cryopreservation offers hope and flexibility to individuals and couples planning their future families. If you are considering egg, embryo, sperm, or tissue freezing, consult a fertility specialist today to explore your options.

Contact us to learn more about fertility preservation and start your journey today!