I think that there is a difference between what age is ok to bring up children rather than being the donor so to speak. I really do think it depends on situation - you can get some really young men in their 50's and old men in their 30's. My hubby is 45 and I am 38 so we know that we are not done in yet lol but we have decided only to have 1 for us to give 1 baby full attention and energy - not sure if we would have the energy for 2 xxx