Ah, definitely within our lifetime. I'm pretty certain that we will see the first trans women give birth. I wouldn't be surprised if it was as soon as within a decade or two.
That's not to say, though, that the success rate of childbirth among trans women won't be extremely low at first. I think everyone here will be long dead before the success rate is above 50%.Of course, such developments WOULD necessitate the creation of more resolute processes by which transgender individuals could transition. Right now the system is still extremely shaky,but I think a development such as functioning reproductive organs might potentially jump-start the rest of the restructuring and solidifying of the psychological transition. In fact, there might come a day when gender identity might be potentially diagnosed by scientific mental examinations. You never know. YOU NEVER KNOW.
And this is just mankind's transitional period anyway. In about a million years the entire human race will be comprised of fully-fertile hermaphrodites anyway.