Reading this question I was struck by an underlying assumption present in some answers that generational length (~25 years) would remain about the same. But the thing is, that may not be the case. In our world, the best time (biologically speaking) for us to have children is fairly young, while the best time for us (psychologically and economically speaking) to have children is significantly older. Having children later increases likelihoods of various complications, genetic disorders, etc.
But in Star Trek, we have two fundamental differences in play. One is advancement of medical technology such that we can assume age of the parent is no longer a limiting factor. The other is economic changes which mean it is no longer more stable to have a child later in life. The limiting factors are therefore when you feel like having a child and what you want to do with your life, what sort of career and personal development you want to have before you have a child. Picard's brother, for example, is clearly a somewhat older gentleman but with a young son. On the other hand, his ambitions were relatively simple- he wanted to run the family vineyard.
So, obviously there are going to be those who want to be a parent early and often. But do we have any sort of commentary about time between generations lengthening in general in the Star Trek universe? Or, alternately, anything to show that the average generational length has remained more or less the same?