Eggs are removed from the patient and fertilized in a test tube with the sperm of a partner or donor. The resulting embryos are then frozen and stored. It takes about two weeks from the start of a woman's menstrual cycle to get eggs to use for in vitro fertilization; waiting may be a problem with a fast-growing cancer like acute leukemia. Also, the hormones given so that more than one of a woman's eggs will ripen may stimulate breast cancer cells to grow, so researchers are trying to use different hormone combinations to make hormonal stimulation safer. Another option would be to simply harvest the one egg that ripens in a natural menstrual cycle, but the chance that the egg will fertilize, survive freezing and produce a live birth when transferred to the woman's uterus is less than 10%.
Some women opt to have the eggs frozen unfertilized, particularly if they are not in a committed relationship. Later, the eggs can be thawed and in vitro fertilization attempted. Egg-freezing remains experimental and has resulted in fewer than 200 live births around the world.
Some women have parts of their ovaries removed surgically and frozen before cancer treatment. Although some centers are banking ovarian tissue before cancer treatment, this technique is still experimental and has resulted in only a few pregnancies worldwide.
For women receiving chemotherapy, one option may be to take a hormone that puts the ovaries into temporary menopause during treatment. However, many infertility specialists doubt that the hormones truly prevent the chemotherapy from damaging the ovaries. The hormone shots are expensive, and it is possible that they could have some impact on the success of chemotherapy.
For women receiving radiation treatment, it may be possible to move the ovaries out of the radiation area surgically. Sometimes they can be relocated at the sides of the pelvis, out of the radiation target field. There is a 50% chance that women will resume menstruating after this procedure.
Other options for becoming a mother after cancer treatment include using donor embryos or eggs, having a surrogate (where another woman carries the child), or adoption.