This advice is best if you plan not to have children. I believe it's well understood now that the best time to have kids (for the health and development of the children) is when you're young, since autism and other problems have much higher risk when the parents are older. Unfortunately, knowing this won't help me now, since I'm in my later 30s already. :)
correct me if I'm wrong but the age of the father matters much less to the developing fetus than the age of mother, no?
I guess I am also assuming you are of the male gender.