I can understand where you are coming from OP.
I have never thought about it that way, and I don’t know what the stats are.
But from personal experience I feel a little overprotective over teen mums, and hate the way that they are generally treated as a category, or how they are judged as a category.
I was a teen mum, and with help and support I was able to complete studies, get into work, climb the career ladder and contribute towards society. I know many women who have had children before 25, and are the hardest working people I know - because we don’t have time to mess around. And actually have caught up to peers by the time we are 30s. I have friends that have kids in their 30s, and some choose not to work or work part time instead. Same thing - just timelines have rotated .
I think what frustrates me is the prejudice towards teen mums. And now that we are seeing a rise in infertility, I think we need to stop judging women for when they have children - across the board.
If you have them young, as long as you look after them and get the support, it’s no one’s business. If you choose to wait, well good for you, but that also isn’t anyone’s business.
Also when I was younger raising my child, I didn’t have much of a social life, so didn’t see my friends as much. That is fine. But now that a lot of them are in their 30s/40s - and I have more free time so can actually hang out with them - I get comments of “you are so lucky that you have your children”. Sometimes I want to say “well you are lucky you have your experiences” - we all make choices. But it can’t be easy if you feel like you are fighting against the biological clock - which I see a lot in my friendship circles.