i'm 54 and i agree with davis.
got two grown up daughters and two young boys i raise on my own and although i keep telling myself that i shouldn't have more kids, if the situation arose and it happenned, i would welcome an addittion or two to my family.
kids are a hassle:
frustrating
unappreciative
full of shit
difficult
etc.
but rewarding nonetheless and as long as proper provision is made for their welfare after you croak, i think it is ok to become a father at 100.