Oocyte (Egg) Freezing – Fertility Preservation for the Future

Please note: Oocyte Freezing is still an investigational process that is not yet widely accepted and outcomes remain significantly lower than traditional in vitro fertilization.

Women usually do not know they have fertility problems until they try to become pregnant. However, in certain circumstances, a woman may know ahead of time that her ability to reproduce is in jeopardy, allowing her to make the decision to preserve her fertility for the future. A common example of such a scenario is someone about to undergo chemotherapy or radiation treatment for cancer, both of which are known to damage a person's reproductive potential. At our practice in the Fort Lauderdale, Florida region, oocyte (egg) freezing, through a technique known as vitrification, offers women hope for future fertility.

Stimulation and Retrieval
Egg Freezing and Storage
Thawing and Fertilization
Reproduction after Oocyte Freezing

Stimulation and Retrieval

Although it is possible to conduct oocyte freezing with immature eggs or even sections of ovarian tissue, the most effective technique for egg vitrification is to induce maturation of the eggs and collect them as would be done for IVF. Fertility medications are used to stimulate the development of multiple ovarian follicles and induce ovulation. Before the eggs can be released from the ovaries they are retrieved using a procedure known as ultrasound-guided transvaginal aspiration. During this procedure, an ultrasound probe is used to see the ovaries and surrounding structures while a very fine needle is guided through the vaginal wall and into each ovarian follicle. Gentle suction is used to remove the egg and fluid from each follicle, and it is then stored in an individual container, where it will be prepared for oocyte freezing.

Egg Freezing and Storage

Once the eggs are collected, they are examined and mixed with a cryoprotectant solution before being rapidly cooled. The traditional method for the cryopreservation of sperm, embryos, and eggs involves a slow freezing technique. This is effective for sperm and embryos, but problematic for egg freezing, as oocytes are large cells that contain a good deal of water and have a tendency to be damaged by the formation of ice crystals. Vitrification, however, is a technique that involves very quick freezing and does not allow ice crystals to form, thereby preventing damage to the eggs.

Once the eggs have reached the appropriate temperature, they are transferred to long-term storage, where they will be kept in liquid nitrogen until they are ready to be used.

Thawing and Fertilization

When the patient is ready to use her frozen eggs, they will be retrieved from storage and gently warmed. After thawing, the eggs are examined and those that have survived the oocyte freezing process will be fertilized in vitro or through intracytoplasmic sperm injection (ICSI). The resulting embryos are transferred into the patient’s uterus as normal.

Reproduction after Oocyte Freezing

Early attempts at egg freezing showed very little promise. The rate at which eggs survived the freezing and thawing process was very low and even lower was the rate of successful conception and pregnancy. Using the vitrification technique, however, fertility experts have seen significant increases in the numbers of oocytes that are viable after being frozen and thawed.

Contact Our Fort Lauderdale, Florida-area Practice

Contact us in the Fort Lauderdale area of Florida to learn more about oocyte (egg) freezing and how vitrification improves the chances of success with this fertility preservation method.