Is the egg the body selects the healthiest?

[sirensong]

It would make sense if the ovaries selected the best egg to be dominant and get released. Is that the case or is it actually more random? If you have more follicles does that mean there might be a better chance of a higher quality egg in any given cycle, because it's beaten more competitors, or is it irrelevant?

I will read up but asking in case anyone already knows. I realise that women often end up with degree level knowledge about all of this!

I don't know but I'm definitely interested in the answer

I'm interested to know!

I doubt it or miscarriages, and birth defects wouldn’t happen

No.

It sort of doesn't and does? As far as I understand it, the body gathers several follicles, which I believe are randomly gathered, but then the best, healthiest, follicle releases the egg.

No, it's random chance, which is why many miscarriages happen once the body identifies genetic abnormalities/incompatibility with life. I've had 7 MC's sadly, including genetic testing on some of the foetuses. We were given great comfort from knowing all of my eggs weren't 'bad' and it was random.

Yes. I went to see one of the top IVF doctors in London. He said that the body releases the best eggs first and bluntly by the time I’m in my late thirties the body is working with eggs that aren’t good. I said do you mean my best eggs went down the toilet in my teens and I now have the dregs left, and he said (politely) yes. He said I’d have far more chance conceiving with a frozen egg from a woman in her twenties than with my own fresh eggs.

The ovaries release the best egg. And the egg chooses which sperm to allow in ( the first sperm to the egg isn't always the winner). And then your uterus does a quality control check on the egg. If not enough tryspin is detected, your uterus will reject implantation. Miscarraiges and birth defects still happen because the quality of an egg solely depends on what others you have available I guess. And sometimes your uterus control check is too high or too low, meaning it could reject perfectly healthy embryos but doesn't. I suffered recurrent miscarraiges so I researched alot of this. Even with a high ovarian count i still had multiple losses in a row.
It's all so technical. So much more goes into conceiving then I ever imagined.

Yes the healthiest eggs are released sooner, this is why women's fertility declines with age and risk of miscarriage increases

So sorry for your losses. It's great you were given that reassurance.

Good point. I suppose I was thinking issues could also originate with the sperm, the compatability of the gametes, low ovarian reserve, strength by one measure but not another, or sheer bad luck of the whole cohort available for selection on a given cycle having a problem.

The proportion of eggs that are abnormal increases with age as a general thing. But on any given cycle when (for example) 15 follicles start to develop and one follicle then becomes dominant and is eventually released, while the others die off, has that happened as a result of selection within that group of 15?

It would be a weird evolutionary blind spot for there to be no basis to the selection at this stage. This is what I want to read up on. Seem to be mixed responses on the thread so far.

@sirensong sperm quality does play a role. I think the blame was put on women and egg quality for so long that now it's hard to believe that sperm play a huge part in miscarraige rates too. One of the first tests me and my partner were referred for was his sperm quality as I have 2 children from a previous and my partner didn't.
You should read professor lesley regan recurrent miscarraige book. She works at the top miscarraige unit. It's an eye opening read into how it all works and what affects things. If you want to learn more about all of this. Its a great book. Eye opening to be honest.

Although it's about miscarraiges it really dives into how our bodies select which follicle etc.

Did you proceed with any treatment?

For context, I've partly asked this question because I find the underlying science really interesting for its own sake. Party because I'm over 40 and early on the path of trying to conceive.

I have been told I have good ovarian reserve but I realise quality will nonetheless be diminished. So I'm wondering whether to try naturally for a while (because maybe my body will select the best of a wonky bunch each month) or whether I should go straight to a clinic to bank and test as many embryos as possible.