A 1-year-old who was born at 21 weeks has been named the world's most premature baby by Guinness World Records.

A baby born at 21 weeks' gestation in Iowa City, Iowa, has celebrated his first birthday, earning a Guinness world record for being the most premature baby.

An Iowa infant who was born at just 21 weeks of gestation celebrated his first birthday earlier this month with a new title – “the most premature baby” of all time. Nash Keen weighed only 10 ounces when he was born on July 5, 2024 – 133 days before his due date, early enough to land him in the Guinness Book of World Records.