Ann is 36 years old, she is single and hasn’t met “Mr. Right” yet… She feels her biological clock is ticking, and is afraid of not finding the right partner in time to have children.

Marie, age 35, is an executive employee at a big multinational company. Although she would like to have a family, she believes that motherhood at this time will affect her career.

Both of them are wondering the same thing: Should I freeze my eggs?

Egg freezing, also called oocyte cryopreservation, has been around for many years now. But lately it has been extensively discussed in the media, especially since Facebook and Apple announced that they will be paying egg freezing for their female employees (read more here).

You have most likely heard of egg freezing, but how is the procedure? Is it safe? When to do it? Is it a sure thing?

In this article we will clarify the most important aspects of egg freezing and discuss some realities you need to know in case you decide to embark on this venture…

What is egg freezing? Why should I consider it?

Egg freezing means that a woman’s eggs are extracted from the ovaries, frozen and stored for future use.

Fertility declines with age, and this is due to ageing of the ovaries and eggs (oocytes). Unlike men, who produce spermatozoa throughout most of their lifetime, woman are born with a lifetime’s egg supply: we have about 2 million immature eggs at birth, when we reach puberty there are about 300.000 left, and each month we lose several thousands. By the time we are 30 years old, 90% of the eggs are already gone, and only 3% have remained when we reach 40.

But it’s not only quantity that matters, it’s also quality. As the body ages, the oocytes age as well, and their genetic material may become damaged. This is the reason why older women have reduced fertility, but also increased risk of pregnancy loss and having a baby with certain defects such as Down syndrome.

Unlike the eggs, the uterus is not affected by ageing and is able to carry a pregnancy in the 40s and beyond; this is true even for menopausal women.

Therefore, if we pick up the eggs and freeze them, eggs’ quality will remain unaltered with time: let’s say you freeze your eggs at 30 years old, and you put them back in your 40s, your eggs will still be 30 years old!

Who are the candidates for egg freezing?

–Women who want to delay motherhood for social reasons, usually due to career or study obligations, or because they are not in a stable relationship. This is the most common reason egg freezing is requested and carried out, although scientific societies’ opinions worldwide are divided in this matter. While the European Society for Human Reproduction and Embryology (ESHRE) endorses it by stating: “Oocyte cryopreservation should […] be available for women […] who want to protect their reproductive potential against the threat of time”, the American Society for Reproductive Medicine (ASRM) stands more cautious, concluding: “There are not yet sufficient data to recommend oocyte cryopreservation for the sole purpose of circumventing reproductive aging”.

Although social egg freezing will be the focus of this article, there are other situations where egg freezing is, beyond any doubt, an invaluable tool:

–Women diagnosed with certain cancers. Some cancer treatments such as chemotherapy, radiotherapy or surgery may damage the ovaries, leading to sterility. Thus, freezing the eggs before therapy may preserve fertility in these women.

–Women with high risk of going into early menopause:

• women carrying a faulty gene or chromosome known to cause early menopause;
• those with a strong family history of early menopause.
• those having a defective gene (such as BRCA1 and 2 genes) related to high risk of ovarian cancer, when removal of the ovaries is considered. In such women, if childbearing has not been completed, egg freezing may be an option before surgery.

–Certain couples undergoing in vitro fertilization (IVF):

• When for religious or legal reasons the embryos cannot be frozen. This is a common situation in countries such as Italy, where embryo freezing is forbidden by law.
• If the man is unable to collect sperm, or when men with severe infertility do not have no sufficient spermatozoa to fertilize all available eggs. In such cases, the eggs can be frozen for use at a later date.

How is the procedure I should go through to freeze my eggs?

In order to freeze the oocytes, a woman undergoes a hormonal treatment, aimed to stimulate the ovaries to produce multiple eggs. There are several protocols for that -the so-called short and long protocols- depending on ovarian function and also how urgent the procedure is (e.g. when egg freezing is done before cancer treatment).

Initially, a medication is used to turn off natural hormones, sometimes together with birth control pills. After that, hormone injections are self-administered during 10 to 14 days to mature the eggs.

When the eggs are ripe, they are aspirated through the vagina with the aid of a needle, under ultrasound guidance. The procedure is usually done under mild sedation. The eggs are immediately frozen, in most centers with a method called vitrification.

Once a woman decides to attempt pregnancy -this may be months or years later- the oocytes are thawed, injected with a single spermatozoon and left in an incubator to fertilize. After two to five days, the resulting embryos are transferred into the uterus with a thin catheter.

It should be mentioned that some women from whom few eggs are retrieved may need to undergo several stimulation cycles in order to have a reasonable number of oocytes cryopreserved (the ideal number would be 20 to 30).

 Age issues…

What is the ideal age to freeze my eggs?

From the biological point of view, the answer is straightforward: the younger, the better. Here is why: a woman in her 20s is expected to have 15 to 25 eggs available for freezing. Since the oocytes are of good quality, about 4 to 5 eggs will be needed to produce one baby (some eggs will not survive the thawing process and others will not fertilize). Someone in her 40s, though, will produce in the best of the cases 8 to 10 eggs, but (statistically speaking) 25 eggs may be needed to produce one baby, because the eggs will be of lower quality…

But at what age should a woman take the decision to freeze her eggs? This question is more difficult to answer. Ovarian function is not equal for every woman. While certain women in their early 30s have already diminished ovarian function, others in their 40s have excellent hormonal levels… An ideal time frame would be between 30 and 35, but again, we should be cautious as this may not apply to every woman.

In order to help you decide when to freeze your eggs, some experts suggest to monitor regularly the ovarian reserve by measuring a hormone called Anti Mullerian Hormone (AMH), which is very reliable to show how the ovaries work.

What is the age limit to freeze my eggs?

According to ESHRE, cryopreservation for women older than 38 should not be recommended, unless prior assessment of the ovarian reserve justifies the procedure. In many centers, the upper limit is 43, because this is the age when pregnancy rates drop dramatically. Again, there may be exceptions according to a woman’s ovarian function.

What is the age limit to use my frozen eggs?

As stated above, the uterus is not affected by ageing. There have been reports of women having children -with egg donation from a younger woman- in their 60s. But there is a point where a pregnancy will not benefit neither the woman, nor the children. The ASRM advises against embryo transfer (either fresh or frozen) in women over 55, because over that age the maternal and fetal risks seem to be higher. Many centers set the limit of 50, which is the age limit established by law in many countries.

How well does egg freezing work?

Out of all the frozen eggs, about 90-95% will survive the thawing process. When the thawed eggs are fertilized, the results are comparable to those with IVF using fresh oocytes: 36 to 65% pregnancy rate, according to different studies. Like with IVF, success rates are clearly linked to maternal age at the time of freezing, the younger the women, the higher the pregnancy rates.

These results, although  impressive, show that egg freezing is not a 100% guarantee of success; of all women freezing their eggs about half of them will become pregnant.

How long can the eggs remain frozen?

Egg freezing is a relatively recent procedure, but the practice of freezing embryos has been around for many years, and pregnancies have been achieved with embryos frozen for more than 20 years. So we expect that, most likely, the same will apply to frozen eggs.

Is it a safe procedure?…

…For the woman?

Obtaining oocytes for fertility preservation is a very safe procedure, although not entirely without risk of complications. The medications taken to stimulate the ovaries, the procedure of egg pick-up and the anesthesia required are all possible sources of complications. Briefly, the medications’ side effects are usually mild, as one of the most feared complications in assisted reproduction, the ovarian hyperstimulation syndrome, is very rare (this is because the embryo transfer is deferred). The remaining risks are estimated as follows: risks from the anesthesia: in 1/10.000; risk of severe hemorrhage from the egg retrieval procedure: 1/2.500; risk of infection: less than 1/500. For a more detailed analysis of complications, check here.

…For the baby?

To date, more than 5.000 babies have been born from frozen eggs, and the available data seem to be reassuring. The largest study on this subject analyzed 900 babies; no increased rate of birth defects was observed. Of course, since this is a relatively new procedure, it will take many years of follow-up to confirm egg freezing safety.

Unanswered questions…

There are still many controversial issues and debate surrounding egg freezing; from women feeling egg freezing is “as liberating as the contraceptive pill”, to those believing this is just a -very lucrative- business, pushing women to consider “a must” to freeze their eggs and to feel “irresponsible” if they don’t do it. This debate has been even more fuelled by Apple and Facebook’s decision to pay the procedure to their employees…

At the present time, some questions remain to be answered:

• Will egg freezing become a standard procedure, a sort of insurance each woman will have?
• Will it push women to become mothers at a later age, leading to a generation of older parents?
• Is egg freezing the future of fertility? Will this procedure contribute to medicalize conception?
• Can we / should we fool our biological clock?
• Will companies force women to devote their lives to their jobs, to eventually “discard” them in their 50s? Should women’s efforts be directed towards achieving more benefits for working mothers, rather than getting egg freezing payed?
• What will happen to all the frozen, unused eggs?
• What are the psychological risks of the procedure, especially for women who froze their eggs but did not become pregnant?

The bottom line…

• Egg freezing is not a warrant for future pregnancy. Delaying childbearing you may risk missing the opportunity to eventually have a child.
• This procedure should be regarded as a “plan B”: an emergency measure in case you fear you won’t be able to have children before running out of eggs.
• Before deciding to freeze your eggs, you should discuss extensively the procedure with your doctor, in order to learn risks and chances of success in your particular case.
• What is more important, all women should be aware that there is an age-related fertility decline in women. Therefore, when possible, you should not delay childbearing. The biological clock does tick!

 

More info at gofertile.eu

References:

The American College of Obstetricians and Gynecologists: Oocyte Cryopreservation. Committee Opinion, Number 584 -January 2014

ESHRE Task Force on Ethics and Law: Oocyte cryopreservation for age-related fertility loss. Hum Reprod. 2012 May;27(5):1231-7.

Practice Committees of American Society for Reproductive Medicine; Society for Assisted Reproductive Technology. Mature oocyte cryopreservation: a guideline. Fertil Steril. 2013 Jan;99(1):37-43.

Cobo A1, Diaz C. Clinical application of oocyte vitrification: a systematic review and meta-analysis of randomized controlled trials. Fertil Steril. 2011 Aug;96(2):277-85.

Egg Freezing for a Future Pregnancy: What to Know. WebMD

Photo credits

Intro: Getty images; oocyte: scitechdaily.com; career woman: youqueen.com; hormone injection: fssc.com.au; intra cytoplasmic sperm injection: Wellcome images, Flickr.com; ideal age: Tatyana A, Flickr.com; age limit to use frozen eggs ffemagazine.com; pregnant heart: Olivier Martins, Flickr.com; Egg freezing: midlandfertility.com; safety for the woman: theage.com.au; for the baby: Daniel James, Flickr.com; unanswered questions: Stefano Corso, Flickr.com; young pregnant woman: Tips Times Admin, Flickr.com.