Dr. Anupama.R , Director & Chief consultant Reproductive medicine, PRAN Fertility Centre, Trivandrum.
Autologous human oocyte cryopreservation allows storing woman’s eggs to be used later by the same donor when therapeutic or elective reasons induce women to postpone motherhood. In the case of non-medical motivation, this practice is termed social egg freezing. By shifting the awareness from a medical procedure to social relations, frozen oocytes are becoming polemic bio-objects, which pose new questions about timing related to fertility decline and motherhood.
In late 2012, the American Society for Reproductive Medicine (ASRM) and the Society for Assisted Reproductive Technology (SART) announced that they would no longer consider oocyte cryopreservation (i.e., egg freezing) to be experimental. In 2014, the American College of Obstetricians and Gynecologists (ACOG) endorsed the ASRM–SART guideline. Notwithstanding these cautions, the use of social egg freezing (i.e., nonmedical egg freezing) is increasing in the United States. This increase has been linked to a number of complex and interrelated reasons for delayed childbearing, including personal, professional, financial and psychological factors.
How are human oocytes frozen?
Egg freezing is a process that involves the hormonal stimulation of the ovaries, followed by transvaginal retrieval and subsequent freezing and storage of a woman’s viable eggs. Although egg freezing can occur using slow-freezing or vitrification (flash-freezing) protocols, the latter technology has increased oocyte survival post-thaw and improved pregnancy rates, and is the method recommended by the relevant professional medical associations. Vitrification involves the use of cryoprotectants and ultra rapid cooling in an effort to solidify the cell to avoid the formation of ice crystals. The ASRM–SART practice guideline estimates that the survival rate of oocytes after vitrification and thawing is 90%–97%, the fertilization rate is 71%–79% and the implantation rate is 17%–41%. The clinical pregnancy rate per vitrified and thawed oocyte is 4.5%–12 %. However, it should be noted that these data are generally derived from oocytes obtained from women less than 30 years of age. Studies examining the success rates of social egg freezing remain limited, and egg freezing does not guarantee a successful pregnancy or live birth.
Benefits of social egg freezing
Egg freezing has been used since the late 1990s for fertility preservation for young women with cancer who are at risk of sterility as a result of their cancer or its treatment.Even without a cancer diagnosis, a woman who discovers she has a BRCA mutation might choose to undergo a prophylactic oophorectomy to decrease her risk of cancer. Egg retrieval and egg freezing in advance of the removal of her ovaries can be a means of preserving potential future fertility. Autoimmune diseases and hematological diseases are treated with chemotherapy, and thus involve the same risks to future fertility.Premature menopause does not involve gonadotoxic therapies, and is not itself a life-threatening condition, but it does cause an abnormally early end to a woman’s reproductive years. A woman at risk for premature menopause (or for premature ovarian failure due to a number of genetic conditions) might be motivated to freeze her eggs.
Egg freezing has been used since the late 1990s for fertility preservation for young women with cancer who are at risk of sterility as a result of their cancer or its treatment.Even without a cancer diagnosis, a woman who discovers she has a BRCA mutation might choose to undergo a prophylactic oophorectomy to decrease her risk of cancer. Egg retrieval and egg freezing in advance of the removal of her ovaries can be a means of preserving potential future fertility. Autoimmune diseases and hematological diseases are treated with chemotherapy, and thus involve the same risks to future fertility.Premature menopause does not involve gonadotoxic therapies, and is not itself a life-threatening condition, but it does cause an abnormally early end to a woman’s reproductive years. A woman at risk for premature menopause (or for premature ovarian failure due to a number of genetic conditions) might be motivated to freeze her eggs.
Medical risks to mother
Perhaps the most important medical risks associated with egg freezing are those that can result from ovarian stimulation, such as ovarian hyper stimulation syndrome. Suggestions have been made that ovarian stimulation may increase the risk of breast, uterine and other cancers. However, reports of cancer are limited and conflicting, further research is needed. Women who attempt to achieve a pregnancy using their frozen–thawed eggs will be subject to the risks of IVF. These risks include multiple pregnancy, pregnancy-related high blood pressure, premature delivery, operative delivery and infants with low birth weight. Medical risks to women and their future offspring that are associated with pregnancy at an advanced age (i.e., expected delivery after age 35 yr) should be communicated to women who ask about social egg freezing. Women who become pregnant at an advanced age are at an increased risk of gestational diabetes, preeclampsia, cesarean delivery and preterm delivery of a baby with low birth weight. However, these risks vary widely, depending on the woman’s health status, and increase with maternal age at delivery.
Risks to offspring
In addition to the harms associated with premature birth and low birth weight, there is evidence of “a slight increase in the risk of congenital structural abnormalities” with IVF, and some research suggests that there may be a small but increased risk of cancer and structural cardiac anomalies for these children. Further research is needed to confirm the risks
Financial aspect
Increased media attention, as well as employer and private insurance coverage of social egg freezing, may result in growing pressures on young women to freeze their eggs. Media coverage often emphasizes the potential benefits of egg freezing and ignores or downplays the associated risks. Reported costs range between $5 000 and $10 000 per stimulated cycle. In India the expense is around 1.5 lakh. For long term storage, it charges `50,000 per year. Physicians should inform women that provincial health insurance programs do not currently cover social egg freezing costs and no provinces offer funding for IVF after social egg freezing. Patients should give careful consideration to both present and future costs.
Conclusion
In light of the controversial nature of social egg freezing, with competing perspectives and information available from a variety of sources, Medical professionals have a unique opportunity to assist women in accessing accurate and balanced information about their reproductive health. In fact, given that egg freezing is no longer considered experimental, the American Society of Clinical Oncology now recommends that health care providers discuss the cryopreservation of unfertilized oocytes as an option for preserving fertility in female patients diagnosed with cancer. Medical professionals should frame discussions about this practice within the broader context of reproductive health and family-making to assist women in making informed choices.
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