Ovarian Tissue Cryopreservation - Basics
When a girl or woman is diagnosed with cancer, the patient and physician will discuss treatment options.
Cancer treatments such as radiation or chemotherapy can damage the ovaries and pose a threat to fertility. If there is enough time before treatment begins, and a woman is old enough, the most mature fertility preservation option is embryo banking.
However, if a girl or woman is too young, is not a candidate for egg or embryo banking, or does not wish to undergo hormonal injections prior to cancer treatment, she may consider ovarian tissue cryopreservation.
Ovarian tissue cryopreservation is a process where an ovary is removed before damaging radiation or chemotherapy treatment. This ovarian tissue is then frozen so that it may later be used to restore a woman's fertility.
How does this process work? First, ovarian tissue is removed at an Oncofertility center during a 30- to 45-minute outpatient surgery called laparoscopy, which is done under general anesthesia. Recovery is usually very quick and a woman may begin her cancer treatment in a matter of days after the surgery.
Once the tissue is removed, an Oncofertility specialist will cut the ovary into thin sections called cortical strips. These strips contain small, immature follicles.
Next, the strips are frozen and stored for future use. Through participating hospitals within the Oncofertility Consortium, patients may choose to donate 20% of these strips to research. The other 80% would remain the property of the patient for their future use.
There are two ways a woman may be able to use her frozen ovarian tissue: ovarian tissue transplant and in vitro follicle maturation.
An ovarian tissue transplant is when surgeons thaw the frozen cortical strips and, in a second laparoscopic procedure, implant them into the patient. The hope is that the immature follicles within the transplanted strip will begin to develop as they would in a normal ovary. This is still a new and investigational procedure but it has resulted in some successful pregnancies and births. It is important to discuss this procedure with your physician because it is not recommended for women with certain types of cancer, especially leukemias, lymphomas, and ovarian cancers.
The second way a woman could someday use her stored ovarian tissue is by in vitro follicle maturation. Rather than implanting the cortical strips, doctors isolate immature follicles from the strips and grow them in the lab.
The follicles must be matured under careful conditions. When a follicle is fully grown, the egg is extracted and fertilized by sperm. After a few days, the fertilized egg, or embryo, is implanted into the uterus with the hope that it will lead to a successful pregnancy.
In vitro follicle maturation is still an investigational procedure that has not yet resulted in pregnancies. The goal is to develop this procedure over the next several years so that women can one day use the follicles in their frozen cortical strips to achieve a pregnancy. This is one of the research projects being done by the Oncofertility Consortium.
Because each fertility preservation option has its own risks and expected success rates, it is important to talk with your doctor to determine the best fertility preservation strategy for you.