Preservation and Postponement of Fertility – A Field Emerging From Infancy

Sunday, 26 September 2010 18:10

The science of Reproductive Medicine has seen amazing advances in the last several years. But some of the most exciting advances have come in the area of preservation of female fertility. Fertility preservation is of utmost importance to women of reproductive age who have developed a cancer or disease that threatens their ability to have children in the future. And these new advances can't come at a more important time. It has been estimated 1 in 250 adults will be a cancer survivor. In recent surveys, 75% of patients with cancer have stated that they want children in the future, 80% feel that their cancer experience would make them better parents, 67% would want a child even if they were to die young.

 

Nonetheless, there remains a sharp divide between patient interest and health provider education on the topic of fertility preservation. Only 60% of survivors diagnosed with cancer in young adulthood recall discussing cancer-related infertility, and in a survey of 697 women diagnosed with breast cancer before the age of 40, 72% of respondents stated that they had discussed infertility with their physician, but only 55% were satisfied that their concerns about childbearing were addressed.

There are other reasons women choose to postpone or preserve their fertility other than for the purpose of preparing for toxic chemo or radiation therapy. Women in western countries have also increasingly delayed the birth of the first child to a later age. With the growing popularity of assisted reproductive technology, many women have been given the impression that female fertility may be successfully influenced at any point prior to menopause. Unfortunately, the assumption that fertility can simply be resumed at a later time is erroneous and can often result in future subfertility. On the other hand, the uterus does not seem to play a significant role in age-related fertility until much later. This phenomenon makes methods of fertility preservation that focus specifically on preservation of the egg particularly attractive.

Fertility preservation has been traditionally limited to cryopreservation, or freezing, of embryos. But embryo cryopreservation in the context of fertility preservation has a few critical pitfalls. First, it requires that the female patient has a male partner or uses donor sperm to fertilize retrieved eggs. Second, ovarian stimulation must precede oocyte retrieval for in vitro fertilization. This characteristic necessitates a delay that may be unacceptable in the case of a cancer patient requiring rapid initiation of chemo- or radiotherapy. Third, the high estrogen levels associated with ovarian stimulation may be contraindicated in women with estrogen-sensitive malignancies such as breast cancer.

Newer techniques have recently been developed that can overcome these limitations. Many fertility centers now have the ability to freeze oocytes, or eggs, a process which eliminates both the need for sperm and the ethical quandries that sometimes arise with freezing embryos. While egg freezing is still considered a new technology, over 1000 babies have been born to date from frozen and thawed eggs. In cases where the time needed for ovarian stimulation is not available, ovarian tissue with intact eggs can be surgically removed, and frozen. This tissue can later be thawed and re-transplanted, allowing women to resume menstruation and become pregnant. In the near future, it may even be feasible to freeze, thaw, and re-transplant an entire ovary. Several fertility centers in the United States, Europe, and Israel are currently working on this technology, and early results are very promising.

Reproductive age women have a right to fight for their fertility – whether it is threatened by disease, chemotherapy, or just the passage of time. Similarly, caregivers have a responsibility to inform their patients that there are options available to them when a threat to their future fertility ensues. The first step is to educate one's self about available treatments and to find reproductive physicians who can provide them. Here are some websites that may be of help...

http://www.fertilehope.org/

http://www.asrm.org/topics/detail.aspx?id=455

http://www.isfp-fertility.org/

http://oncofertility.northwestern.edu/