A man can have an unlimited number of babies in his lifetime. This is because a man does not need to be pregnant or give birth in order to father children. Through medical technology, men are now able to donate their sperm and help couples who are unable to conceive naturally. With the growing popularity of surrogacy and other assisted reproductive technologies, more people than ever before are having children with the help of male donors. This means that a single man is theoretically capable of fathering an infinite number of babies over the course of his life - though it would take considerable resources and effort for him do so!