Anecdotally and from what I read it seems that most couples with fertility problems go on to have their own biological children at some point.
IVF seems to have a really high success rate if people have more than 1 round. Of all my friends that have had fertility problems all eventually got their desired child. You always seem to hear of miracle babies of couples who are told they would never be able to have children. I very rarely hear of couples of a younger generation that had fertility issues and didn't get what they wanted in the end, even if it does take around 10 years to achieve.