To worry about my 35YO daughter who is delaying having children to please her partner?

This.

I agree they should both get fertility testing, it will make it real in his eyes and you'll see if he's on board with the reality or just using the wedding as an excuse to kick it down the road again. If he doesn't see the point or says they'll do it after a year of trying, then she needs a more serious conversation.

I wouldn't criticise her plan and say 36 is too old, but I would talk to her about his level of commitment and have her reflect on different outcomes (resenting him if he's wasted her fertile years, for example).

It's great posters have so many friends who were in this situation and it worked out. I know more who either separated when it was too late (he then having kids straight away with a new partner) or who had to throw thousands of pounds and heartache at it. I have one friend who used an egg donor, even though she'd wanted kids years earlier and there is resentment that he's more related to the kids than her and that's his fault.

The 35 cliff edge idea comes from analyses of French parish records of births in the pre-antibiotic age (really - see link) - unfortunately, female fertility is woefully understudied.

https://www.bbc.com/news/magazine-24128176

What does he say other tha not ready? Does he have a reason or a goal that he needs to achieve first?
Obviously fertility goes down the older you get, but i don't think her age here is thw primary issue. It is nat she is with a man who is undecided or doesn't want children. She needs to have a very big talk with him. If he is the same age with no dnet, stable job, house, wedding planned. What is there to not be ready for?

It is so difficult to know with fertility - I got pregnant first time trying (literally) at 37, I have other friends who experienced the same, and others of the same age or younger who struggled. I would suggest a fertility MOT too, then at least she'll know whether it is a risk to wait another year or whether it will make no difference.

It is not uncommon to have children in the 40s these days (and indeed my hospital only considered 40+ older mothers). But it obviously can be a much harder road in terms of fertility treatments etc then.

That’s just not true. It declines but not ‘massively’ it is on a downward trend for years!

Agree with @Llamallamafruitpyjama if DDs partner doesn't go for the testing, then it means he is delaying and not really serious about wanting children now or in the future. Maybe OPs DD should consider if this relationship has legs for the longer term and if he is the right man for her to marry at all.

OP as someone who had her first child at 37 after ttc since before 30, I would highly recommend she really thinks about putting it off any longer as it could take longer than she thinks.

Plus if she wants more than one then she will probably have a very short age gap between the two if she only starts ttc at 36.

Yes! I had secondary infertility at 30 and am in peri menopause now at 33. I wouldn’ t be able to conceive now without IVF and the risks of stillbirth and birth defects rise with mother and fathers age too. I have two friends that have babies with disabilities that had children after 35.

Good idea because if he refuses it’s more evidence he is actually stringing her along. My husband went as soon as I asked when we had secondary infertility, even tho he found it all embarassing.

Understand you're trying to be positive here, but this makes no sense! Your fertility has no bearing on the OP's daughter's fertility - and on their fertility as a couple. Fertility - in general - declines in mid 30s and really speeds up in later 30s, so this is a very real issue for many women.

I think you need to absolutely push her to have fertility testing done and ask her outright would she be ok never having children? I had a friend in a similar predicament who decided to split and she had a baby a year later with a donor and she now has a beautiful much loved 2 yr old little girl and is so so happy! The yearn to be a mother doesn’t ever really go away and she may find the love of her life ends up being her future child. This man is an oddball to me for waiting 12 years till marriage and then again stalling more and making her wait till next year, why? Why why why? I don’t trust he won’t have another Bs excuse. Time to be straight with her so you don’t watch her in her 50s if the marriage doesn’t work out crushed that she never was a mother.

Maybe suggest your DD and partner both get fertility testing to see where they are with this. The risk of leaving it any longer means they may potentially struggle but have the testing outcomes means they can make an informed decision about cracking on or waiting.

I'm not sure what good fertility testing is really going to do her. If she wants a child, she should start trying now whatever the testing reveals.

A fertility test could either panic her or give her a false sense of security. But she will know that the risk of miscarriage and infertility goes up as she gets older. It doesn't mean it will definitely happen to her, but it doesn't mean it won't - no-one can know what's in store for her. I think the most important thing you can do is focus on your role as her mum - make it clear for her that you don't judge her choices and will be there for her come what may. If she did have a bad time, surely you want her to be able to confide in you and not think she'll have to deal with 'I told you so' or your own feelings about being a grandmother?

I’m so sorry, this is an understandable worry.

Encourage her to organise for them both to be fertility tested, then take it from there.

12 years is a long time to keep her waiting for a proposal and a baby - I don’t need to tell you that. But if she leaves him, aged 35, she’s got to start over finding someone else.

Is he a good egg (other than this dragging his feet in these incredibly important areas) ?

This means nothing. I had good fertility, on paper. My DH didn’t. Hence the need for IVF. Even then, my good fertility didn’t prevent the multiple miscarriages; that was another issue that only more complex testing will reveal. Unless OP’s daughter has had her partner’s fertility tested, she has no idea if they can even have children. For all she knows, her partner might be sterile.

I had my first at 36, second just before 40. I didn't feel ready before then, but was incredibly lucky that conceiving our first was easy (second look a little longer). But I got lucky, and many women really struggle after 35. If she knows for sure she wants children, she is really pushing it. What is the argument for waiting until late next year to try? It might seem more convenient that way (after the wedding), but it also increases the chances that it might not happen at all. Fertility testing could be a good idea - I don't know how reliable it is, but if she is given "bad" news, this is at least good ammo to go to boyfriend with, to see if he is serious about actually having children.

Awful behaviour if he's just going to keep pushing this down the line until the music stops. He might not be entirely conscious that this is what he is doing - so perhaps needs a wake up call.

The issue with saying fertility is fine for some later is that fertility does drop off earlier for some women. I’m 33 and already in peri menopause (confirmed by my specialist with labs). Some women can have babies at 36 and later but others like me would really struggle. I already had secondary infertility at 30 and our fertility clinic had a strict rule of no patients over 35, as their outcomes are not as good.

I'd have the same worries. 12 years is such a long time together to wait for a child. I'm also in peri at 38 so although plenty do conceive late 30s, even 40s there are also many who won't. There isn't anything you can do though, she is an adult who can make her own decisions. I would have left the relationship by now if I was your DD but it sounds like she has weighed it up and decided the relationship is worth the risk.

My friends partner did this, basically strung her along until she was menopausal and she then was the problem. She’d have made a fabulous mum 😢 He always believed he should have been with a model type and was secretly keeping himself available. Still together, she not so secretly resents him 🤷‍♀️

We actively started trying for a baby when we got engaged, before our wedding. It took another 7 years, fertility treatment and multiple miscarriages before DS was born.

There is, nor should be, no reason why your DD cannot just start trying now. Nothing will magically change after she’s got married, other than being another year down the line.

She should also rationalise with herself just how badly she wants a child; ie is she prepared to go it alone if she becomes pregnant and her reluctant partner seems even more reluctant.

she could consider egg freezing though it isn’t a guarantee and is already past the optimal age for it. It’s expensive but you could always help her with the cost. Then if he does change his mind she still has that as a backup.

She's better having the baby once they're married.

Having been together do long, they should have cracked in with marriage and kids before now tbh.