PHILADELPHIA — Egg and ovarian tissue freezing should not be marketed or offered to healthy women as a means to defer reproductive aging, according to a new report issued by the American Society for Reproductive Medicine.
Although the techniques hold promise for female fertility preservation, a lack of sufficient data on success rates and safety issues means these procedures should be performed only experimentally under Institutional Review Board guidelines and only in women who face potentially sterilizing treatment, the report states (Fertil. Steril. 2004;82:993-8).
Despite these recommendations, Extend Fertility, a Boston-based company that promotes egg freezing to healthy women as a means of extending their biological clocks, says it plans to continue offering the service through participating fertility clinics.
The company is offering the services under IRB guidelines; however, the cost is approximately $15,000 per cycle, and patients are usually advised to undertake several cycles, she said.
Bradford A. Kolb, M.D., of the Huntington Reproductive Center in Pasadena, Calif., one of the company's affiliated clinics, said, “We do recognize the controversy over this issue and do advise patients that this procedure should be considered experimental. It's not a guarantee of preserving one's future” fertility. Dr. Kolb also serves as a medical advisor to Extend Fertility.
Although there is no way to force clinics to follow the guidelines, ASRM spokesman Sean Tipton said that clinics that do not follow the guidelines risk losing their membership with the Society for Assisted Reproductive Technology (SART), an ASRM affiliate.
The cryopreservation techniques outlined in the report are “by no means ready for wide applications outside of investigational protocols,” Marc A. Fritz, M.D., chair of the ASRM practice committee that wrote the report, said during a press conference held at the meeting.
“It was the [ASRM's] view that the worldwide experience with these techniques is simply insufficient,” said Dr. Fritz, professor of ob.gyn. and chief of the reproductive endocrinology and infertility division at the University of North Carolina, Chapel Hill. He added that there have been fewer than 100 births from frozen eggs, although there have been no developmental or chromosomal abnormalities noted in any of these children. And although ovarian function has been restored in several cancer patients after ovarian tissue cryopreservation and transplantation, the first birth in a woman who underwent this procedure was announced only last September.
The ASRM report is less restrictive when it comes to patients who face potentially sterilizing chemotherapy or radiation therapy.
In this context, both oocyte and ovarian tissue cryopreservation techniques could be considered, the document states. In addition to cancer, this would include indications such as bone marrow or stem cell transplantation; oophorectomy for cancer prophylaxis or benign conditions; and certain autoimmune diseases.
In such cases, ovarian tissue freezing may be the only fertility-preserving option for women who do not have enough time to complete ovarian stimulation cycles before chemotherapy or radiation treatment. On the other hand, for women who do have time, egg freezing is less invasive than ovarian tissue freezing, and may be more attractive to women who do not currently have a male partner, the committee wrote.
The report also outlines safety issues concerning these techniques. In the case of ovarian tissue cryopreservation and subsequent transplantation in cancer patients, “there is a legitimate concern regarding the potential for reseeding tumor cells,” particularly when it comes to leukemias, neuroblastomas, and breast cancers. The document recommends that histological, immunohistochemical, and chromosomal evaluations should be performed on multiple harvested ovarian tissue samples before cryopreservation to minimize this risk.
There is also little known about the potential for malignant transformation of transplanted ovarian tissue. And in the case of oocyte cryopreservation, concerns remain regarding the effects of cryopreservation on the meiotic spindle of the oocyte and the potential for chromosomal aneuploidy or other karyotypic abnormalities in the offspring, according to the report.