[fr_freak]

Worst case scenario is 1 in 25 chance of having a child with trisomy 21.

I've always wondered: does it make any difference if the child is the first child the woman has had or the tenth?

[Melas]

I've always wondered: does it make any difference if the child is the first child the woman has had or the tenth?

No difference in trisomy 21. A woman is born with all the eggs she'll ever have, which is the root problem here. Staying pregnant doesn't keep the eggs any younger, or age them any faster.