While the 20s may be the time a couple would be at the peak of their reproductive well-being, having a baby (or two) can make people refocus and reprioritize life- from life, travel, jobs, housing, money and leisure, especially in the first couple of years. Thus, having a baby in your 20s can be much more psychologically draining compared to parents who have a baby later in life.
In some cases, having a baby too early, before the age of 25 could also bring on additional risks to maternal health. But that isn’t always the case.
Again, with a shift in social norms, planning a baby doesn’t seem ideal for people in their early 20s and isn’t usually the first choice if you ask them.