Dr. Feinberg is a board-certified in both Obstetrics and Gynecology and Reproductive Endocrinology and Infertility. She completed her residency in Obstetrics and Gynecology at Northwestern University in Chicago, IL, and completed a three-year fellowship in Reproductive Endocrinology and Infertility at the National Institutes of Health. She is nationally recognized in the field of Reproductive Medicine and was invited to serve on the Editorial Board of Fertility and Sterility and on The Society for Assisted Reproductive Technology Practice Committee.
Eggsurance Q & A with Dr. Eve Feinberg
Q. What do you think is the optimal age for women to freeze their eggs? Why?
A. On one hand, you want to say as young as possible, however on the other hand we do not know how long frozen eggs are good for – are they good for 5 years, 10 years? Also, what is going to happen to the woman over the course of her reproductive life? We don’t want to subject someone to egg freezing at 21 if at 25 she is going to meet the love of her life and have babies.
Therefore, I think 30 is an optimal age – because fertility is still excellent in most women at 30 and they are mature enough to understand the concept of egg freezing. However, I worry about the implications of egg freezing and future fertility. Would women look at relationships differently if they had the reassurance that they had frozen their eggs? I think egg freezing brings up many social implications.
I would tell her not to rely on this too much — it is insurance and it is good technology, but this is your plan B. It is an excellent plan B, but don’t give up on your plan to have a baby.
Q. Clinics freeze only mature, or M2 eggs, typically what is the percentage of mature eggs retrieved from one cycle?
A. From a very basic scientific perspective, eggs have 46 chromosomes and at the time of ovulation an egg needs to kick out half of its chromosomes so that it can later be fertilized. An M2 is a mature egg that has kicked out half of its chromosomes – we know this because we see those 23 chromosomes in a structure called a polar body. We only want to freeze mature eggs because when they have 23 chromosomes as opposed to 46 they are able to accept sperm in the future.
That said, the maturity of eggs retrieved depends upon a few factors: age of the woman, stimulation protocol, and experience of the person running the stimulation protocol. It can be extremely variable between protocols based on the combination of medication used to stimulate the ovaries. I have had cycles that I have canceled based of the way the follicles have been developing. I have then changed the protocol and gotten great results. Maturity rates largely depend on the stimulation protocol being used in conjunction with a woman’s own fertility potential – however, there is no one universal protocol that is optimal.
Q. How many retrieved eggs are considered a good amount?
A. The million dollar question… I think that it is age dependent. We are starting to get more data from the use of frozen donor eggs and egg banks. Based on data that came out of IVI (Instituto Valenciana de Infertilidad), they determined that the optimal number of eggs for a woman under 30 is 6. From 6 high quality eggs, we tend to get four high quality embryos. However, as women get older the number of eggs needed will increase due to diminished egg quality.
I counsel my patients who are in their mid-30s that 15 eggs to achieve one live birth is probably a safe bet. Is it an exact science? No, there is no data that is published, but if you look at maturity rates, fertilization rates, embryo development rates in general you are going to see 80% maturity, 75%-80% fertilization and 50% blastocyst development and on average two blastocysts equal one baby. Therefore, the attrition rate is such that somewhere around 15 eggs will equal one child.
Q. When is it advisable to cancel an egg freezing cycle?
A. I think it is always a very in depth discussion that you have with your physician to set the expectations based on your ovarian reserve testing and what you are capable of producing ahead of time. I counsel my patients beforehand and let them know what we can realistically expect from their cycle. But, if I see that someone is not performing to what they are capable of, then I would cancel the cycle. I do not want to waste my patients’ time and money. For example, if someone has a resting follicle count of 15 and I put them on a protocol and see that they only have 3-4 follicles developing I would cancel the cycle because I think that they are capable of so much more.
If a woman has been on birth control pills for many years, especially if she had irregular cycles before the pill, and then wants to freeze, should she wait one or more cycles while off the pill before freezing?
There is not a ton of data behind this – but, my gut feeling is yes. I would tell my patients to go off the pill for an entire cycle, do ovarian reserve testing and then stimulate. When you are on the pill for a long time you tend to be very suppressed and require a lot more drugs to receive the same response. I like to see patients off the pill for at least one month to get a sense of what their ovaries are capable of producing.
Q. The ASRM removed egg freezing’s “experimental” label in 2012, how do you think this will affect the future of egg freezing?
A. I am a member of the SART Practice Committee, which is the group that helped to shape the recommendation, and I believe that the decision was long overdue. I think first and foremost it will remove some of the stigma of egg freezing. IVF never had an experimental label, which is really interesting because the implications of IVF are so much greater. Also, to put an experimental label on something like egg freezing when sperm freezing never had an experimental label was extremely detrimental in regard to insurance coverage.
From an insurance standpoint, it will encourage insurance companies to offer greater coverage for egg freezing. If infertility is a covered benefit then egg freezing should be a covered benefit too. There is also a tremendous amount of discrimination that goes on with insurance companies against single women and same sex couples– perhaps with this label being removed it will help to release some of the grounds that the insurance companies had stood upon. Also, I think from a public acceptance stand point that the time has arrived for egg freezing now that studies show that there have been 1,500 babies born and increases in congenital anomalies have not been seen…I think that we are on the cusp of something much larger than we anticipated.
Q. What is the one thing you would like to tell women about egg freezing?
A. This is very close to home for me as one of my best friends is going through this right now. I would tell her not to rely on this too much — it is insurance and it is good technology, but this is your plan B. It is an excellent plan B, but don’t give up on your plan to have a baby. Ultimately, you want to parent in a reasonable amount of time. Egg freezing is your back up plan and your safety net against the potential to use a donor egg.