to wonder what will happen to the discarded embryos?

[mrsmootoo]

It must be awful to carry a genetic disorder and see a child suffer. It must be fantastic to think there is a way of having a healthy child. However, I have not seen anyone talk about how the parents will avail themselves of a healthy embryo from which the nucleus has been discarded and which their own will replace. Isn't the discarded one a potential baby? Who will offer their healthy embryos to be used in this way? I don't necessarily have a problem with it, I'm just interested in the logistics and the reality of this being actual people, not just scientists in a lab etc. Have I missed something? Can anyone explain?!

What embryo? I thought what is discarded is the (unfertilised) donor egg's nucleus - so no more a baby than any other unfertilised egg. Then the fertilised nucleus from the parents is inserted.

Aren't they using eggs? So, removing the nucleus of the egg? So, no more a person than your period?

Unless you want to ban any form of IVF (which I'm sure some people do) then I don't see where you're going with this. Wasn't there a report saying around 30 embryos are discarded for every IVF child born?

Anyway, potential personhood isn't the same goddamn thing as an actual person, as has been explained again and again, and yet the goady suggestions continue. Digging up an acorn seed isn't the same as chopping down a tree and you won't be in court for illegal deforesting, if you want a village idiot's analogy for it.

Without a nucleus, surely there is no embryo?

Furthermore a blastocyst (the point at which an "embryo" is transferred back into the uterus on day 3,5 or 6 after fertilisation) is a bunch of cells. A heartbeat doesn't 'form' until about 6.5 weeks.

So whilst there is a lot of concern that embryos get discarded, they really are not babies, iyswim?

I agree with BarbarianMum but wouldn't you have an issue with IVF in general if you're worried about discarding embryos? I've considered donating eggs in the future and I wouldn't have a problem with people using/testing/discarding any embryo that resulted from the donation.

I'd be much more worried about preventing horrible genetic diseases than what happens to a sting of DNA.

Embryos don't have a nucleus, do they? Because they are multi-cellular, right? An egg is no more a human or an embryo than a sperm is, surely. And we flush enough sperm.

And just to add that until there is complete, guaranteed anonymity when donating an embryo, there is no way on earth I would donate any of mine. I would dearly love to help a childless couple but am not willing to risk a future child coming to knock on our door one day.

If I've understood the diagrams on the BBC website correctly, it's the nucleus of a fertilised embryo that is removed. Not just an egg. So yes the nucleus from the donor embryo that could have potentially become a child will be discarded.

Lots of embryos from IVF treatment are discarded. That already happens. So I don't see that itself as a particular concern with 'three person' IVF treatment.

I thought it was the mitochondria that was to be replaced, not the nucleus?

Every cell in the human body (and therefore every cell in an embryo) has a nucleus...

Surely then it's a zygote rather than an embryo as people understand it...

I am assuming it's done at this stage: www.advancedfertility.com/zygotes1.htm

So the egg has been fertilised by the sperm but hasn't yet started dividing. You can see the two pronuclei in the middle. This is the stage the day after the eggs and sperm are mixed together, which counts as Day 1 in IVF treatment.

If that makes any difference to anything.

What I meant was not that a multi-cellular organism doesn't have any nuclei, but that it doesn't have 'a nucleus' which can be removed. A zygote does...

MrsTerryPratchett - I agree with you, zygote would be the more accurate term. But it's more than just using an unfertilised egg, which I think some people above have suggested.

I am unsure about the potential risks in the technology in terms of affecting the 'germ line' and changes carrying on through generations. Not anti, just unsure.

But the discarding of embryos point I think is a red herring unless you're going to ban IVF full stop.

Chocolate, while you are not anonymous, you certainly would not have a child "knocking on your door."

Lol at it being a baby tho!

Just a clump of cells, no matter what stage

Marmot I have a big fat question mark in my head about epigenetics and IVF in general. That worries me. Getting rid of the nucleus of a zygote doesn't.

its estimated that many more eggs are fertilised than ever implant, so your body has probably discarded plenty of zygotes too.

I don't see any difference between a seperate egg and sperm and the same things that happen to have been stuck together for a day or two. I can't see the latter as any more important or sacred than the former.

I don't think there are so many embryos discarded.

Many eggs may be retrieved but not all will be mature enough, then not all will fertilise, then not all will fertilise 'normally', then not all will still be there on day 3. Day 4 waiting and then day 5 likely even less to transfer or freeze.

I was so worried before IVF about what would happen to all the embryos I couldn't use. Turns out I needn't have worried.

But the London hospital I used actually say in their patient info most people end up with NOTHING to freeze from a fresh cycle. Ironically, it's the people who are lucky enough to have something to freeze who are most likely to get pregnant from that fresh cycle.

With the move now towards aiming for blastocyst stage most of the embryos have fallen by the wayside.

With this new trend I dont think there are these large numbers of embryos lying around that you might think.

IVF involves the creation of embryos or lots of fertilised eggs that never have the chance to grow into babies. In fact lots of fertilised eggs never become implanted in nature. Intro fertilisation is already used to prevent genetic disease.

Personally I think that replacing faulty mitrocronia is a brilliant idea if it can be shown to be safe. If the technique has been shown to work in animals the it's time to try it in humans.

I've had 3 rounds of IVF and had 3 embryos returned. I think around 15 - 18 were created.
You are asked at the beginning what you want to do with any remaining embryos. I chose to allow them to be used for further research as if someone hadn't done that in the past then IVF wouldn't have been perfected or improved.

there is absolutely no need to use an embryo, you use a donor egg.