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?!

I admit I am not totally up on the technicalities and at what stage the fertilized egg is officially classified as an embryo. But the donor egg is fertilised by sperm before the pronuclei are removed so it's not 'just' an egg is it, fertilisation has taken place? But the mitochondria come only from the egg, is that right? And I assume for some reason you can't take the healthy mitochondria from an unfertilised egg or another cell or they'd be doing that?

I suppose for people who have a problem with discarding embryos from IVF (not me) it comes down to when life begins - at fertilisation, at some defined stage of embryo development, whenever. But as I say above I don't think there's an ethical difference in terms of discarding embryos between this and 'regular' IVF.

kim your diagram says that both eggs are fertilised by the sperm and then nuclear DNA is removed...so by definition this is an embryo/zygote?

I agree with marmot's last paragraph

But read step 1

Kim147 - step 1 in the diagram you've posted is fertilisation. Step 2 is the removal of DNA. Meaning the eggs are fertilised, surely?

In The Times today the diagram definitely states that a healthy embryo is needed - the nucleus from that is discarded and replaced by the nucleus of the two parents. Maybe zygote is the term as it's so early, but it's not just an unfertilised egg. So I suppose it's the same dilemma IVF parents have with possibly unused embryos.

I had IVF and had no dilemma over the other four embryos they didn't use. All of them were doing something strange in their cell multiplication and were badly graded anyway.

I did IVF and I donated leftover so-called 'healthy' embryos for research, no problem. You learn the hard way that 2-5 day embryos are merely cells. They weren't anywhere near being babies. I have had enough failed embryo transfers not to invest too much in the embryo/cell stage.

Of course, when we first made some embryos I thought they were all incredibly precious. And in a way they were. With them we stood a chance of a baby, without them there would be none. They are a start. But I learnt early on that these were not 'waiting babies'. There is a lot of tosh talked - especially in the U.S. - with people donating their 'snowflakes' so that they can have a 'chance to live'. Gawd help us! They are not that special - how many normally fertile people make embryos inside eachother all the time and they fail to catch on, implant or make it down the fallopian tube or get eaten by a fibroid - who knows what goes on in those uterine depths? The fact that these ones are made in a petrie dish, monitored and visible, doesn't make them any more special than the millions that nature discards.

What is a healthy embryo anyway? Do you mean a viable embryo - perhaps that is the word you are searching for? A viable embryo is just that - a maybe, a possibility. Lots of viable embryos don't defrost properly, don't implant properly, don't do lots of things. There are so many slips betwixt cup and cervix that there's really no point worrying. They are a starting point. A bloody sight better than nothing, but a long way from a baby. Discarding them or losing them or donating them is not huge. When you have 'lost' a number of embryos, you know that there is only so much you can invest in them. Does that make sense?

Lots of fertilised eggs are discarded in the process of conceiving a child naturally. It doesn't worry me at all. There are millions of "potential children" that don't come into the world. (There's probably at least one potential child not being made while we all sit here on Mumsnet ). A clump of cells that could potentially turn into a baby if all kinds of circumstances are put into place doesn't hold much significance to me.