Freezing eggs for non-medical reasons enables women to delay parenthood. Is it right for you?
Suspending time’s effect on the human body may seem like a fantasy taken from the H. G. Wells’1895 novel The Time Machine. But in the field of fertility it’s a reality when we consider eggs (oocytes).
Cryopreservation is the cooling of cells and tissues below zero temperatures in order to stop all biologic activity. This technology applied to eggs allows young women more flexibility in their decision of when is the right time to begin family building. A woman can suspend her fertility in time, so to speak.
The decline in fertility with age is serious science. Fertility in women decreases gradually but significantly starting at 32 years and decreases more rapidly after 37 years of age. The reserve of eggs becomes depleted both in number and quality.
If a younger woman freezes her eggs (oocyte cryopreservation) when they are more viable and plentiful, she has the opportunity to use them years later to become pregnant through in vitro fertilization (IVF).
After many decades of research and investigation, in 2012 the American Society for Reproductive Medicine declared that egg freezing was no longer labeled as “experimental,” opening the opportunity for women and fertility clinics to embrace the freezing option. Vitrification or the “flash freezing” of eggs, embryos – and even ovarian tissue – have increased the survival rates and ultimate viability of reproductive cells frozen by the process. The pregnancy success rates using vitrified oocytes have increased significantly making the practice even more popular. New egg banking facilities storing donor and autologous (self-use) oocytes are now common.
Egg freezing is an option for any woman who wants to be a mother, just not right now. However, it is important that women realize that egg freezing is an option, not a guarantee of future pregnancy. If your fertility potential is currently low, egg freezing will not improve your chance of conceiving in the future.
Women undergoing cancer treatments such as chemotherapy and radiation may become infertile and single women who haven’t yet found their partner may be concerned about their ticking biological clock. Egg freezing is a good back-up plan to preserve fertility.
Embryo cryopreservation is still the best strategy for preserving fertility in women who have a committed male partner or are willing to use donor sperm. The single most significant factor in pregnancy success rates with fresh or frozen embryos is the age of the female partner. Embryo cryopreservation provides a predictable likelihood of achieving pregnancy based on the number and quality of the embryos stored frozen.
For decades, men have been able to freeze their sperm successfully, giving them an option women didn’t have. That’s because fertile men produce over 30 million sperm in one ejaculate. Even though about half of the sperm don’t survive the freeze thaw process, there are still 15 million or more available to fertilize an egg. Eggs are precious in number, harder to collect and have unique biological properties which have made successful egg freezing technologically more challenging.
Procedures used for IVF have fine-tuned ovarian stimulation and the egg collection process which have made access to eggs in higher numbers more readily available. The application of vitrification to egg freezing produced such impressive results that, for the first time, the whole IVF process didn’t have to be done in real time using freshly retrieved eggs.
IVF can be done in suspended time, using frozen eggs. Warming of the eggs followed by fertilization and embryo culture allows for an embryo transfer to occur many years after egg collection. For many women, egg freezing has become a kind of fertility insurance in case pregnancy does not occur as planned.
From science to social science
Women open to the prospect of egg freezing must come to terms with complex issues.
- How many eggs do I need to freeze?
- How do I know I won’t be able to get pregnant later naturally without egg freezing?
- If I freeze my eggs now, am I conveying to my partner that he isn’t good enough?
- Should I delay motherhood just because I can?
- What if I freeze my eggs, postpone motherhood and the frozen eggs don’t work?
- What are the obstetrical risks of advanced maternal age?
Every woman needs to know that egg freezing is not a guarantee of successful pregnancy. If a woman freezes her eggs, the possible outcomes are that she gets pregnant on her own before needing the frozen eggs, she doesn’t get pregnant with the frozen eggs or on her own, or she gets pregnant with the frozen eggs. It is also a possibility that some women may decide that motherhood isn’t right for them.
Whatever the case, if a 30-year-old woman freezes her eggs, she is more likely to get pregnant at 40 using her frozen eggs for IVF than she is using her 40-year-old eggs. In egg freezing, the rule of thumb is the sooner you do it, the better.
The fertility specialists at the Loma Linda University Center for Fertility & IVF can guide women towards those decisions. Not everyone is a good candidate for egg freezing. Women interested in preserving fertility should speak with a fertility specialist.