Terminology Tuesday: Fertility Preservation
Happy New Year! I have received a number of questions concerning preserving fertility. I would like to begin the new year with a discussion on fertility preservation. In 2007, a meeting of an expert advisory panel convened to discuss the emerging focus on fertility preservation to help women and men have biological children. The findings of the panel were published in 2009. I present highlights from the panels' report.
Q- What is fertility preservation?
A- According to a report published in the respected journal, Fertility and Sterility, The preservation and restoration of fertility are key aspects of the goal of enhancing the likelihood that women and men can have biological children. The report goes on to say that Providing options for preserving fertility in men, women, and children is not only an important reproductive health issue but a quality-of-life consideration as well.
Q" Who can benefit from fertility preservation?
A " The report states that Among those at great risk for infertility are childhood and adult cancer survivors. An estimated 800,000 young adult men and women living in the United States have been diagnosed with cancer. The chemotherapy and radiation used to treat cancer can irreparably damage the body's reproductive tissues and render both sexes infertile. Although treatment and survival are the primary focus of health-care provider and patient alike, with cancer survivors living longer it is now appropriate to consider their quality of life after treatment, including the possibility of becoming parents.
The report goes on to say, Certain other patient groups may be candidates for fertility preservation, including women with endometriosis or uterine fibroids, and patients treated with chemotherapeutic agents for nonmalignant conditions such as autoimmune diseases and collagen-vascular disorders. In addition, woman with other medical conditions which can result in an accelerated decline in ovarian function, such as those women with Lupus, Turners syndrome, and those who are carriers of Fragile X, may benefit from fertility preservation.
Some people are at risk for impaired fertility or infertility because of exposure to occupational or environmental hazards and thus might want to take measures to preserve their fertility. For example, military personnel might want to take measures to preserve their fertility should exposure to radiation, biologic, or chemical agents later compromise their fertility. Furthermore, some individuals live in communities that could disproportionately expose them to pesticides, lead, and other toxins.
Q- What are the current options for preserving fertility?
A- The panel stated that Current fertility preservation options are limited.
They go on to state that Techniques for preserving male fertility include sperm cryopreservation, testicular sperm extraction, testicular tissue freezing, and hormonal suppression. Of these, sperm cryopreservation is the most widely available standard procedure for postpubertal males.
Among the techniques available to females seeking to preserve their fertility are embryo cryopreservation and cryopreservation of oocytes or ovarian tissue. Embryo cryopreservation is the most widely available and successful fertility preservation technique today, although its use is limited to women who have spouses or male partners, or who are willing to use sperm cryopreservation. Preserving fertility through the cryopreservation of ovarian tissues or oocytes"although still in experimental stages"would increase the chances that children or single women could someday become parents even after exposure to chemotherapy or other agents that can cause infertility.
The freezing of eggs (oocytes) is a far more difficult process, but is becoming increasingly more available at fertility centers across the country. With oocyte cryopreservation, eggs are retrieved from a woman following well established IVF protocols. Unfortunately, for woman with cancer there may not be enough time to complete an oocyte cryopreservation treatment cycle prior to life saving treatments.
Q- But aren't these procedures still considered experimental?
A- The freezing, or cryopreservation, of embryos and sperm, is well established and widely available and is not considered experimental. Tens of thousands of children have been conceived through artificial insemination using frozen sperm, and through frozen embryo transfers. The freezing of testicular tissue, ovarian tissue, and oocytes (eggs) is still considered experimental.
Q- What are some future options for preserving fertility?
A- The report states that Preventing reproductive failure would be an ideal approach. Research is under way to evaluate treatment with gonadotropin-releasing hormones in conjunction with chemotherapy, inducing a transient prepubertal state that might reduce the damage to reproductive organs and thereby prevent oocyte death during cancer treatment. Other strategies under development include producing oocytes from stem cells and regenerating oocytes by inducing natural mechanisms.
I am hopeful that the combination of greater survival rates for cancer patients than ever before with the brilliant technologies of fertility preservation, many individuals will be able to realize their dreams of having children despite treatments that have the potential to derail those dreams.
Source: Lamar CA, DeCherney AH. Fertility preservation: state of the science and future research directions. Fertil Steril 2009;91:316"9.
Dr. Lowell T. Ku, M.D. is a leading Reproductive Endocrinology and Infertility specialist at Dallas IVF, one the nation's premiere infertility centers. _ Dr. Ku clarifies the many confusing terms used in the world of Infertility using straightforward explanations.