What Are the Success Rates of Egg Freezing?

If you're going to spend the money and time to freeze your eggs, a reasonable question to ask is how likely it is to work. The answer, unfortunately, is not as simple as it seems.

In general, the chance of achieving a successful pregnancy using IVF treatment (which is how you would use your frozen eggs) is about 2%-35% for each cycle, depending on the age of the eggs used. This doesn’t sound that great, but to put it in perspective, the chance of success in ART treatments is roughly six percent higher than your odds of conceiving without assistance on a given month.(1, 2)

However, some clinicians on our Expert Panel actually quote IVF success rates of up to 50% per cycle. This is most often the case when the eggs are younger, there are more eggs retrieved during the cycle, and when preimplantation genetic testing is conducted on embryos prior to implantation. Because freezing, thawing and IVF are not fail-safe processes, some doctors recommend doing multiple egg freezing cycles to bank as many eggs as possible.

But, we’re still dealing with “known unknowns.” The truth is that even after your eggs are retrieved (i.e. once you know how many mature eggs are suitable enough to be frozen), you won’t know for sure if any one of these eggs will be capable of becoming a healthy baby one day. One reason for this is that there is to date no technology that can accurately measure the quality of your eggs. In lieu of this, embryologists follow specific guidelines to determine which eggs are most mature. The logic being that mature eggs are more likely to have gone through all the phases of chromosomal processing in order to be deemed good quality. Despite this, as it currently stands, only eggs that have been successfully fertilized by sperm to become embryos can truly be termed good quality.

Speaking of sperm, let’s not forget about the other side of the equation! Even if you have an infinite number of quality eggs, it takes two to tango. The quality of the sperm can obviously have an impact on the future success of your eggs, too.

“There is no good way to test whether the eggs that women have frozen are of good quality (have normal chromosomal makeup). The only way to know if the chromosomes are normal is to fertilize the egg with sperm, create an embryo and then biopsy the embryo and perform preimplantation genetic testing on the embryo. If the embryo has a normal number of chromosomes, then you know that the egg that it came from is also normal.” - Dr. Diana Chavkin, HRC Fertility, Los Angeles

So, in short it’s currently impossible to know with any real certainty whether your eggs are good quality or not until you use them. Despite the unknowns, there are some indicators to help forecast the likelihood that one or more of your eggs will become healthy babies one day, metrics that you can use as a rule of thumb:

It depends on how old you are when you freeze your eggs, and how many eggs you freeze

There are other variables, too, such as your individual health and medical history, the practitioners’ skills, the quality of the lab, and other lifestyle factors that positively or negatively affect the quality of the eggs retrieved.

The sooner you freeze, the higher the chance of a baby

Your response to ovarian stimulation medications could change from month-to-month, or with different treatment protocols, just as your own menstrual cycle can. As a result, the calculation is unique to each woman and impossible to accurately predict individually. However, as a rule of thumb, the quality and quantity of eggs you’re likely to retrieve in your egg freezing cycle will decrease with each year older you become. In 2017, Harvard scientists created the world's first evidence-based model to help women and doctors gauge the likelihood of success by age, to assist in family-building planning. According to this model, assuming you have a normal ovarian reserve, one cycle of egg freezing at age 35 gives you an 80% likelihood of having a baby using those eggs, regardless of the age at which you use them, whereas if you freeze your eggs at age 40, you would need five cycles to have the same chance.(3) This is why doctors sometimes recommend multiple cycles of egg freezing to older women.

Note: You might be surprised to see that the number of mature eggs retrieved increases again in a woman’s early 40s. Doctors report this can be the case with natural conception, too. Older mothers are more likely to ovulate more than one egg in a cycle and have twins, perhaps functioning as biology’s “last hurrah.” But despite this increase in eggs retrieved, the chances of them being quality are low. This is why even if you retrieve two more eggs at age 41 than if you were 40, your chances of having a baby are still the same (25%).

So, overall, the likelihood of your frozen eggs leading to a healthy baby in the future rests on both the quantity you freeze and the age at which you freeze them (which is indicative of the quality of the eggs.)

Although the unknowns and lack of certainty can feel frustrating, one way to think of it is to flip it on its head and focus on the certainties we do have: that each year older you get the likelihood of you conceiving a healthy child naturally will fall and if you do need IVF, the likelihood of you having a healthy baby using your younger frozen eggs would be greater than using your older fresh eggs.

The more eggs you freeze, the higher chance of a baby

The road from egg to baby is full of obstacles. Many things can prevent an egg from reaching the finish line, from the skill of the doctors managing the stimulation cycle, to the quality of the eggs retrieved, and even the laboratory environment. Basically, it’s a numbers game. Here are just a few of the obstacles that your eggs must overcome (based on conservative estimates):

• At freezing: 15-20% of the eggs retrieved may not be mature enough to be frozen.(4)

• At thawing: 85-90% of eggs are likely to survive the egg freezing and thawing process. (5) However, according to Dr. Chavkin, if you freeze only good quality eggs then you’d have close to 100% thawing success but if you freeze immature and poor quality eggs then your chance of survival would be less.

• At fertilization: Not all of your previously frozen eggs will be successfully fertilized by sperm and effectively transformed into an embryo. According to doctors on our expert panel, the fertilization rate is between 70% to 80%, assuming that the sperm is of adequate quality.

• At implantation: Less than half of embryos resulting from your previously frozen eggs will successfully implant. This can range from 17-40% depending on the age you froze your eggs, which is roughly the same rate as fresh eggs of the same age. (6,7,8,9,10) Common health conditions such as endometriosis, obesity, and uterine fibroids can reduce the likelihood of implantation.(11) On the other hand, advancements in genetic testing, specifically preimplantation genetic screening (PGS), can increase implantation rates. That’s because once all embryos are tested for quality, only the one(s) with the right number of chromosomes are implanted. This test does come at an additional cost ($3,000-$7,000) but could dramatically reduce the number of IVF cycles needed to achieve a successful pregnancy, especially if you were over 35 at the time of freezing. (12,13) Not only that, but it can help reduce the devastating emotional impacts of failed implantation and miscarriage.

• During pregnancy: The miscarriage rate following assisted reproductive technology (ART) treatment is 15%, which is comparable to that following natural conception.(14)

In other words, even a high-quality egg may not survive the journey to becoming a baby, which is why a higher number of frozen eggs increases your chances. Of course, good quality sperm is responsible for the other half of the pregnancy equation.

Still, there are no guarantees

Every healthcare provider should be upfront in telling you the facts and, if you feel like you’re getting oversold and the facts are being glossed over, you don’t have to go back. It’s as simple as that. There are many wonderful and wise fertility doctors out there whom you can trust to give you the real facts, while also giving you options for your future, so don’t settle for care from someone who isn’t placing your best interests front and center. (More on how to pick a clinic later.)

“With egg freezing, it is important to realize that we do not have the extensive outcomes data, (pregnancy rates most importantly) that we have generated with IVF over the past twenty years. We can make educated assumptions about the likelihood of success based on past cycles using cryopreserved eggs and embryos, but we will not have generated these numbers for quite a few years.” - Dr. David Sable, Healthcare and Life Science Investor

Egg freezing gives you an extra chance of conceiving a biological child in the future, but we all need to keep our feet on the ground as there is actually no guarantee of being able to have a child from those frozen eggs in the future. It might not work. Natural conception should be the goal, with egg freezing representing a backup, not your life plan.

Want more insight on whether or not egg freezing is right for you? Get the full guide in Everything Egg Freezing: The Essential Step-by-Step Guide to Doing it Right.

RESOURCES

1. Analyses of the National ART Surveillance System (NASS) data. Written communication with the Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, August 22, 2019

2. Steiner AZ, Jukic AM. Impact of female age and nulligravidity on fecundity in an older reproductive age cohort. Fertil Steril. 2016;105(6):1584–1588.e1. doi:10.1016/j.fertnstert.2016.02.028

3. Goldman RH, Racowsky C, Farland LV, Munné S, Ribustello L, Fox JH. Predicting the likelihood of live birth for elective oocyte cryopreservation: a counseling tool for physicians and patients. Hum Reprod. 2017 Apr 1;32(4):853-859. doi: 10.1093/humrep/dex008. PubMed PMID: 28166330.

4. Goldman RH, Racowsky C, Farland LV, Munné S, Ribustello L, Fox JH. Predicting the likelihood of live birth for elective oocyte cryopreservation: a counseling tool for physicians and patients. Hum Reprod. 2017 Apr 1;32(4):853-859. doi: 10.1093/humrep/dex008. PubMed PMID: 28166330.

5. Cobo A, Meseguer M, Remohí J, Pellicer A. Use of cryo-banked oocytes in an ovum donation programme: a prospective, randomized, controlled, clinical trial. Hum Reprod. 2010 Sep;25(9):2239-46. doi: 10.1093/humrep/deq146. Epub 2010 Jun 30. PubMed PMID: 20591872.

6. Cobo A, Domingo J, Perez S, Crespo J, Remohi J, Pellicer A. Vitrification: an effective new approach to oocyte banking and preserving fertility in cancer patients. Clin Transl Oncol. 2008;10:268–73.

7. Cobo A, Bellver J, Domingo J, Perez S, Crespo J, Pellicer A, et al. New options in assisted reproduction technology: the Cryotop method of oocyte vitrification. Reprod Biomed online. 2008;17:68–72.

8. Rienzi L, Romano S, Albricci L, Maggiulli R, Capalbo A, Baroni E, et al. Embryo development of fresh ‘versus’ vitrified metaphase II oocytes after ICSI: a prospective randomized sibling-oocyte study. Hum Reprod. 2010;25:66–73.

9. 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. doi: 10.1016/j.fertnstert.2012.09.028. Epub 2012 Oct 22. PubMed PMID: 23083924.

10. Pavone ME, Confino R, Steinberg M. Female fertility preservation: a clinical perspective. Minerva Ginecol. 2016;68(4):458-65.

11. Lessey BA, Kim JJ. Endometrial receptivity in the eutopic endometrium of women with endometriosis: it is affected, and let me show you why. Fertil Steril. 2017 Jul;108(1):19-27. doi: 10.1016/j.fertnstert.2017.05.031. Epub 2017 Jun 14. Review.

12. Scott, R.T. Jr., Ferry, K., Su, J., Tao, X., Scott, K., and Treff, N.R. Comprehensive chromosome screening is highly predictive of the reproductive potential of human embryos: a prospective, blinded, nonselection study. Fertil Steril. 2012; 97: 870–875

13. Adamson, D. If IVF, Then PGD Or PGS? What Genetic Testing Can Tell You About Your Embryo. Huffington Post website https://www.huffpost.com/entry/if-ivf-then-pgd-or-pgs-what-genetic-testing-can-tell_b_59c408dde4b0ffc2dedb5bedUpdated Sept 2017.

14. Schieve LA, Tatham L, Peterson HB, Toner J, Jeng G. Spontaneous abortion among pregnancies conceived using assisted reproductive technology in the United States, Obstet Gynecol , 2003, vol. 101 (pg. 959-967)