Egg or Embryo Freezing
Women can either cryopreserve eggs (useful for women who have not yet met the man they want to be parents with) or embryos (already fertilized eggs, which are more likely to survive the thawing process than eggs alone). The eggs (fertilized) or embryos can later be implanted in the womb for pregnancy. If it turns out the cancer survivor can’t carry a pregnancy after treatment—for instance, because of surgery to remove cancerous reproductive organs—the fertilized eggs or embryos can be implanted in a gestational carrier.
Egg or embryo freezing is the most widely used technique to preserve fertility in women, although it can’t be used for everyone. Not all cancer patients can spare the time for the stimulation protocols necessary to harvest eggs. Also, certain cancers are aggravated by hormone treatments, making this technique unsafe for some women, no matter what their future fertility wishes are.
Some cancers, like breast and endometrial cancer, are hormone sensitive. In these cases, standard hormone stimulation to allow for egg harvesting (to be used for egg cryopreservation or embryo cryopreservation) prior to chemo are not considered safe. “The cancer feeds on the estrogen,” explains Dr. Oktay. A few fertility centers have started offering an alternative IVF protocol that uses Letrozole for ovarian stimulation, a drug that is commonly used in the hormone treatment of female cancer patients. But most fertility specialists don’t offer the procedure yet and still consider it experimental.
In Vitro Egg Maturation (IVM)
In this process, immature eggs are collected from unstimulated ovaries, and then matured in the lab before fertilization. There is no ovulation. The technique may eventually eliminate the need for fertility drugs during IVF. Scientists at Hadassah University Hospital in Jerusalem said they have been able to mature eggs in the lab from female cancer patients as young as five years old to freeze for possible fertility treatment in the future. Still experimental, this technique gives hope of future pregnancy and parenthood to childhood cancer patients who now have very high survival rates, but often require aggressive chemotherapy that causes infertility.
Ovarian Tissue Transplant/Ovarian Transplant
Healthy ovarian tissue (or an entire ovary) is removed prior to the start of chemo, and then reinserted into a woman’s body after she’s completed cancer treatment. The hope is that the transplanted tissue will produce hormones and even ovulate. The tissue may be reinserted in its original spot, elsewhere in the abdomen, in the arm, or sometimes in other areas. The procedure—which helped Annie Dauer become a mother—is still considered experimental. Worldwide, eight pregnancies have been achieved using this technique (although three ended in miscarriages).
