Medical outcomes rapidly become much worse and more expensive for both mother and child as mothers age, as well as precipitously falling birth rates partially attributable to the increased difficulty of having marginal children as one gets older.
I made a comment elsewhere in the thread trying to quantify the way outcomes change with the mother's age [1]. Using the data referenced in that comment, it looks like outcomes are quite stable for the entirety of a woman's 20s and still decent into her early 30s. The real change seems to occur in the early-mid 30s.
In contrast, your parent comment prioritizes women having children at age 20-25. Looking at the data I just referenced, this seems unnecessarily aggressive from a medical standpoint -- do you have a different measure of maternal outcomes in mind? (And from a non-medical standpoint, I'm skeptical that late teens/early 20s are the best time for modern humans to choose the parent of their child.)
