Reproductive endocrinologists should be contemplative when offering and performing elective egg freezing, a medical procedure using clinical and lab techniques similar to in-vitro fertilization (IVF). While many women believe they will have greater control over their future reproductive options through elective egg freezing, some aspects of these technologies could impact their decisions and overall expectations.
Our Hippocratic Oath states to first, do no harm (Primum non nocere). As a corollary to our oath—and as ethical physicians—we must accurately inform our patients about the potential risks and benefits of all care we provide. Here are some things to consider:
1. Egg Freezing Isn't Insurance for Future Fertility
Insurance means you are guaranteed to receive a financial payout or service to compensate you for a loss if a bad event occurs. Although egg freezing is no longer considered experimental by the American Society for Reproductive Medicine, egg freezing as it exists today does not protect women from infertility nor does it guarantee them a pregnancy in the future.
2. Success Rates With Freeze-Thaw Techniques Vary Significantly
Many IVF clinics have little or no experience with thawing eggs or, for that matter, proving that their freeze-thaw techniques can produce healthy embryos and babies in a statistically valid fashion. In other words, most IVF clinics do not currently have sufficient data to show a consistent track record of generating pregnancies from eggs they've both frozen and thawed.
3. Egg Freezing Success Rates Between Clinics Are Difficult to Verify
There is no current central registry or authority where IVF clinics can submit egg freeze and thaw results, or sites where patients can independently verify this data. Between 5% and 10% of women have eggs that don't survive well with current freeze and thaw technologies. The ability to compare individual freeze and thaw data from IVF clinics to national and international averages would be an invaluable tool for these clinics and their patients.
4. Statistics Play an Important Role in an Individual Patient’s Success
Before pursuing egg freezing, it is vital to understand what statistical chances one egg or group of eggs has in leading to a pregnancy in the future. For women in their 20s with a good ovarian reserve, five to eight unfertilized frozen eggs could potentially yield an 80% to 90% cumulative chance of achieving a pregnancy. This information comes from frozen donor egg data, where young egg donors are carefully selected for their presumed high fertility potential.
However, for older women—many of whom are contemplating egg freezing—the statistical outcome is often not as reassuring. How many eggs are actually needed to provide a reasonable chance of future pregnancy for a 35-year-old woman is hard to know with currently available data. Based on IVF statistics, the need could be as high as 20 to 30 eggs, or even higher.
Finally, regardless of a woman’s age, a high percentage of eggs obtained from ovarian stimulation are abnormal. With this information, it’s difficult to predict what insurance or reassurance egg freezing provides.
5. Consider Embryo Freezing Before Egg Freezing
IVF clinics are increasingly perfecting techniques to culture fertilized eggs in the blastocyst stage, which can allow reproductive endocrinologists to use diagnostic tools such as pre-implantation genetic screening (PGS) for chromosome abnormalities and time-lapse analysis of embryo growth. Individual blastocysts cryopreserved by vitrification and warmed properly for embryo transfer lead to healthy pregnancies 55% to 65% of the time if the embryo has a normal chromosome count.
As women get older, the quantity of normal blastocysts produced after each IVF cycle drops dramatically, explaining why the egg to baby ratio goes up with age. For women who are interested in future pregnancy, embryo creation and cryopreservation is a more proven option, as it gives direct and immediate information about future pregnancy potential.
However, by creating embryos with a male partner, women share ownership of their embryos with that partner unless they use an anonymous sperm donor. Some women may, therefore, choose to electively freeze both embryos and unfertilized eggs to help preserve future fertility.
6. Egg Retrieval Has Risks and Unintended Consequences
For some women, egg retrieval can commonly cause mild internal bleeding and the potential for scar tissue formation around the ovaries and fallopian tubes. Egg donors are routinely told this could interfere with future natural conception by preventing an otherwise normal egg from entering the fallopian tube after ovulation.
For IVF patients who have already committed to bypassing their tubes via IVF, the concern about tubal scarring is not as high. But for women looking to electively freeze their eggs, the process could worsen their future chances of conceiving naturally.
7. Predicting Current or Future Fertility Is Difficult
Numerous factors or diseases can impact male and female fertility, but predicting any particular woman's current or future fertility is a challenge. Many fertility problems for women are "hidden," particularly in common issues like tubal disease or endometriosis. Ovarian aging can be partially assessed, but it is not known to what degree current ovarian reserve testing predicts future fertility.
Furthermore, a woman may have perfectly intact fertility but ultimately attempt pregnancy in the future with a man who has poor sperm numbers or quality. IVF could then become necessary for male infertility factors, which might be preferably performed with fresh eggs.
8. The Ideal Age for Egg Freezing Is Unknown
While fertility and egg freezing conversations commonly center around ages like 30, 35, and 40 years, the optimal age to freeze eggs is really not known. Ovarian reserve testing could potentially help provide information about the number of eggs obtained during an ovarian stimulation cycle. This information could then impact the dose of medications prescribed and broach discussions about egg freezing sooner rather than later if the results are less than optimal. However, it is not truly known whether ovarian reserve testing should be utilized in this manner.
9. The Costs of Egg Freezing Are High—and Climb Higher Over Time
Egg freezing requires a significant monetary commitment for medical care to create the eggs, medications to stimulate the ovaries, and laboratory costs to freeze the eggs. In addition, there are ongoing fees to store the eggs properly in a secure and monitored liquid nitrogen freezer.
There are also substantial fees to consider if the eggs are actually thawed and fertilized. Depending on the patient’s needs, it may more cost-effective to save these funds for a future IVF cycle.
10. Things We Should Tell Our Patients
Although egg freezing can and should be part of family building discussions, there is no current scientific evidence that elective egg freezing will enhance fertility for most women as they get older.
As an extreme example, one could argue a woman who freezes her eggs at age 25 to use at age 45 will most likely add to her future fertility options. However, for a woman at age 35 who uses her frozen eggs at age 39, the chances of success are less clear when compared with attempting conception on her own, or even pursuing IVF with her fresh eggs.
Currently, I recommend that all gynecologists and reproductive specialists keep a close watch on IVF and egg freeze technologies, which are destined to improve over time. All reproductive health care providers, including OB/GYNs, should openly discuss fertility and family building goals with their patients. In addition, women and men who strongly desire children should start setting funds aside now for some financial insurance just in case fertility challenges arise for them in the future.