A sperm donor in the US also known as "The Sperminator" recently welcomed his 165th child into the world. According to the New York Post, Ari Nagel, a 48-year-old math professor from Brooklyn has children in almost all the continents of the world. Last Wednesday, he celebrated his latest child, delivered by a mother in Connecticut ahead of Father's Day.

However, Mr Nagel said he will officially retire as a sperm donor when he turns fifty.

"I'll stop when I'm 50. Physically I can keep going, but there may be increased risks for things like autism with older males," Mr Nagel, who will turn 49 in August, told The Post.

The donor has 10 women currently pregnant in the US, Canada, Asia, Africa and Europe. While one of the women is ready to deliver at any moment, two babies are due in July and August.

Notably, the professor keeps a detailed spreadsheet with the names, birthdays, addresses and phone numbers of each child and keeps their pictures pasted on the wall in his office. He also sees many of his sons and daughters often, especially the ones who live in New York, New Jersey and Connecticut and shares pictures of them on his Instagram account.

The professor explained that he will remain committed to maintaining his relationships with his children and added that fatherhood brings joy to his life. While he still hasn't met 34 of his children, he has vowed to "try to be a better father to my 175 children." He said he receives cards and gifts from his kids every Father's Day.

"Some moms don't want me to play a role, but I leave them the option if they change their mind, and most do once the child gets a little older and starts asking questions," he said.

Mr Nagel started his sperm donor journey eight years ago, and since then, he has provided sperm samples to one or two women each week through various methods, whether it is clinical or non-sexual interactions.

However, he has not been lucky when it comes to love. "I have dating apps but haven't had much success finding a woman who wants to date someone with 165 kids and 10 women pregnant. I'm also pretty broke -- which doesn't help," he added.