Lord Winston, who is professor of fertility studies at Imperial College London, warned that it was "a very unsuccessful technology" and said: "The number of eggs that actually result in a pregnancy after freezing is about 1%." He later clarified he was referring to live births.
“It’s not like I would discourage egg freezing. Women should be doing it because it’s the best option they have, but it is not an insurance policy,” says Christos Coutifaris, past president of the ASRM and a professor of obstetrics and gynecology at the University of Pennsylvania. “Insurance policies usually guarantee a payoff. In this case, there is no guarantee.”
https://www.technologyreview.com/2019/08/14/133377/mothers-j...
Just for context, numbers I have been told from multiple fertility doctors are:
20-30% of eggs extracted will fertilize and grow to day 5 blastocysts (aka embryos). The rest will die before reaching day 5.
If the eggs were preserved before the women turned 35, each blastocyst has a roughly 70% chance of being chromosomally normal (which means it is a "good, viable embryo"). For women above 35 years old, the percentage of viable blastocysts goes down (e.g. for a 40 year old, ~40% of blastocysts are viable). This is why is it is important to preserve eggs early.
Each chromosomally normal day 5 blastocyst has about a 50% chance to result in a live birth after it is transferred.
So... if you are 35 years old and start with say 12 frozen eggs, you are maybe going to end up with 2-3 viable day 5 embryos, which are likely to turn into 1.5 children.
Note that this presumes everything is in working order with the woman's reproductive system. Egg quality issues or other issues can make the probabilities for each step decrease.
The article you're linking even says that Winston is using the wrong number, and spends most of its time explaining why he's wrong;
> Lord Winston's 1% figure was referring to the proportion of all frozen eggs thawed for use in fertility treatment which result in a pregnancy and subsequent live birth.
You have plenty of eggs; it's not particularly relevant if a single egg has a 1% chance of resulting in a live birth. The extraction process will gather something like 10 eggs (plus or minus a lot) and then later you fertilize lots of those eggs and select the best candidates for implantation. Selectively quoting the single-egg success rate provides an inaccurate picture of the actual success rates of the overall process (one that's quite obscure and therefore susceptible to people misunderstanding when articles publish misleading advice like this).
Furthermore, research shows that the primary factor determining live birth rate is the age of the eggs. As you get above 37/38 the live-birth rate starts to decrease dramatically. If you freeze your eggs at 35 then implant at age 40 then you don't see the same increase in failure rate as if you just did IVF at age 40.
IF you want to postpone having kids until your 40s, but you know you really want to have kids at that age, then freezing your eggs is a good strategy for those that can afford it.
I'm all for giving women more choices/options around child-bearing; it's already difficult enough for women to balance career and children in modern society.
> Insurance policies usually guarantee a payoff. In this case, there is no guarantee.
If you're looking to buy an insurance policy that guarantees you will get pregnant, I'm sorry to say no such thing exists. All you can do is improve your probabilities. Freezing your eggs does this.
> Women should be doing it because it’s the best option they have
Again your quote is actually arguing for freezing eggs being a good option. What would you say "sound advice" is for women that want to defer having children until their 40s, if it's not freezing their eggs?
I made my statement and posted those quotes because a woman should prioritize children over her career if she desires them. I don't think that there is "sound advice" for women who want to defer having children until they are in their 40s. The odds of a woman having a successful pregnancy are much better if they are under 40. It is easy to see through just the anecdotal reports that many women either thought or were convinced that freezing their eggs succeeds far more often than it actually does in the real world.
Perhaps I was being overly flippant as I don't have the precise distribution. I'm sure it could be zero, I don't know how often that is though. A quick Google gives 10-20 on average:
A 2018 study [1] showed that kids conceived via IVF had abnormal arterial development. IIRC, teenagers had arteries that were as stiff as an average 40-year-old.
Ehhh... the only conclusion I can see there is that more study is warranted. The sample was n=17, normal BMI children currently living in CA with parents who used Stanford for IVF. The control was several years older, and looking at the box plots there's substantial overlap in most measurements.
I mean, sure. We need more research. But shouldn't the null hypothesis be that children born of a novel and extraordinarily unnatural process be less healthy than those born of the usual process?
There's no reason to believe that after all the factors arrayed against IVF children (poor starting egg quality, genetic and cellular damage from ice crystals, mitochondrial damage potential, implantation problems, etc) that the null hypothesis would be "they will be exactly the same".
> (poor starting egg quality, genetic and cellular damage from ice crystals, mitochondrial damage potential, implantation problems, etc)
Well, IVF doesn't necessarily imply any of those things -- in male infertility the eggs may be of high quality, in a fresh cycle the embryos may not be frozen at all, in a healthy mother there may be no implantation issues, etc. There are perhaps hundreds of factors to control for, and the null hypothesis would change depending on the population of IVF children (and their parental history) you're studying.
Lord Winston, who is professor of fertility studies at Imperial College London, warned that it was "a very unsuccessful technology" and said: "The number of eggs that actually result in a pregnancy after freezing is about 1%." He later clarified he was referring to live births.
https://www.bbc.com/news/health-51463488#:~:text=Lord%20Wins....
“It’s not like I would discourage egg freezing. Women should be doing it because it’s the best option they have, but it is not an insurance policy,” says Christos Coutifaris, past president of the ASRM and a professor of obstetrics and gynecology at the University of Pennsylvania. “Insurance policies usually guarantee a payoff. In this case, there is no guarantee.” https://www.technologyreview.com/2019/08/14/133377/mothers-j...