I haven't had a child past 40 but I would have had I had the eggs handy.
I researched all sorts of options including trekking over to the Czech Republic for IVF but had I had eggs, man, I would have had two more by now. You have no idea how difficult, invasive, and expensive IVF is when your eggs are not viable any more.
As it is I'm moving on and going to wait it out for grandkids. I was sad about it for a bit but I've embraced other goals and passions now.
My advice to anyone even potentially interested in having kids past 35 would be to freeze their eggs as early as reasonably possible.