Egg Freezing Q&A with Fertility Expert

As with any new clinical technology, there are inevitably many questions that people ask when it comes to egg freezing. To answer some of the most common questions, we teamed up with fertility expert Dr Paul Serhal, Medical Director at The Centre for Reproductive and Genetic Health, London, and a clinical lecturer at UCL.

What do you say to a woman coming to you for social egg freezing?

The first thing to say is that we have to be very careful in the advice that we give; we cannot ever guarantee a child. My biggest apprehension is a woman saying, “I’ll come and freeze my eggs and this way my family is guaranteed”. Nothing is guaranteed. At CRGH, we currently achieve an almost a 60% pregnancy rate from frozen eggs, in women under the age of 35 years. But more than anything you do this as a sort of insurance policy. And of course it is a question of what are the other options? It was unthinkable even a few years ago to see a woman at a fertility clinic without a partner seeking to freeze her eggs. Now, I see one or two patients coming for social egg freezing every week. They are often highly intelligent professional women with lots going for them, but often haven’t found the right relationship. The important thing is not to tell them you can make a decision about your life or your career based on the fact that you have eggs frozen. It’s an insurance policy, nothing more.

In this context, would you recommend freezing eggs or would you advice freezing embryos?

It is a very good question. If they have a partner, it’s a difficult one. In the past you would freeze embryos but now, you can’t necessarily know whether their relationship will last. We’ve had patients who come for social embryo freezing and then end up getting separated from their partner. So in these circumstances, we actually discourage embryo freezing. At CRGH, we have virtually the same pregnancy rate with eggs, so a woman doesn’t have to link themselves to a particular person if they’re not sure about the relationship. In the sixties and seventies, the advent of reliable contraception was a major revolution in terms of women’s freedom. What we’re witnessing now is the next revolution, which is really empowering women to take over control of their reproductive life. Today, it’s perfectly normal to meet women, often very successful in their thirties or even in their early forties, and they can’t find Mr Nice Guy, and they’re very open about their desire to freeze their eggs. Their family is often encouraging them and supporting them as well, it’s not a taboo at all anymore; everything has changed; and we’ve got to accept that.

Do you think the success rates will get any better than they are at the moment?

I believe that the next advance we will see in this area is the pairing of next generation sequencing with fertility medicine. Say for example, a woman is suffering with recurrent miscarriage. This can be extremely upsetting and difficult to treat. Yet by taking some cells from the very earliest stage of the dividing embryo, you can now sequence the whole set of chromosomes. I believe the future of fertility medicine will be based on genomics, the sequencing and analysis of an organism’s genome, proteomics, the study of the function of proteins, and possibly metabolomics, which is the study of the chemical processes within cells. The embryo produces certain metabolites and if you are able to pinpoint which embryo has got the highest implantation potential you can only improve the pregnancy rate without putting the patient at risk of multiple pregnancy. The HFEA are doing their utmost to restrict the number of transferred embryos for obvious reasons. But it is very difficult to impose rules on clinic because patients differ widely in their response. And I believe the future in IVF is to tailor the treatment to each individual. This is the reason we have partnered with the company Illumina; they are handpicking one clinic in every country to be their flagship partners and they picked us because of our track record in genetic screening. We’re going to launch a program very soon on next-generation sequencing using this technology, and it’s going to be a very exciting journey.

Some women worry that if they freeze eggs on several occasions, they’re using up their egg reserve. Is that true?

There is enough evidence to say that this will not affect a woman’s natural fertility, and it won’t effect the age of menopause. If we do the simple maths, we know that most women are born with a several hundreds of thousands of eggs. Most women have about 25-30 years during which they ovulate. So if a woman releases one egg per month, out of these hundreds of thousands a woman is only using a handful of eggs, around 400 or 500. This is in fact what happens: there’s a pool of eggs that are recruited, and nature will get rid of most of them by apoptosis (programmed cell death). Only one—the leading follicle—will be released for potential fertilisation. What that means is that by stimulating the ovaries, as we do in fertility treatment, you’re merely saving the eggs that anyway were supposed to die. That is why women who are undergoing fertility treatment are not using up their egg reserve. They won’t be wasting anything; in fact, she will be saving those eggs.

Is there is upper age limit for a woman wanting to freeze her eggs?

This is a very good question, and a surprisingly difficult one to answer. I think we have to be very careful in how we counsel women in this regard. It is exactly at the upper limits, women who a trying to get pregnant with their own eggs in their early forties, that genetic screening can be invaluable. Each individual woman must be assessed on her own merits. In the end, all we can do is to honest with our patients, and ensure they have all the facts on which to base their decisions.