The world’s youngest premature baby, Nash Keen, who was born more than four months early, celebrated his first birthday this month.

Ashanti and Nelly celebrated their son KK's 1st birthday with a fun, celeb-filled party and lots of love. See all the adorable details.

A baby born at only 21 weeks of gestation last July in Iowa City, Iowa, has just celebrated his first birthday, and among his gifts is a Guinness world record for most premature baby.

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.

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.

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

Gisele Bündchen thanks fans for birthday wishes, and shared photos of her new baby boy and family celebrations while honoring her late mother who shares her birthday.