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

Nash Keen was born July 5, 2024, at 133 days premature, at the University of Iowa Health Care Stead Family Children’s Hospital in Iowa City, Iowa, to mom Mollie Keen and dad Randall Keen.

A baby born at 40 weeks is considered full term, premature if born under 37 weeks, and a baby born before 26 weeks is a micro-preemie.

Nash weighed just 10 ounces and was 24 centimeters long, or just over 9 inches, at the time of his birth.

Dr. Patrick McNamara, one of Nash’s doctors, told ABC affiliate KCRG in Cedar Rapids he had to tell the Keen family that Nash had a 0% chance of survival based on the data available, but despite the long odds, Nash hasn’t just survived, he celebrated his 1st birthday alongside his family this month.

After six months in the neonatal intensive care unit, Nash was healthy enough to go home. His mom Mollie Keen said he’s a spunky baby who has a big personality and is always smiling.

Nash’s new record tops the previous record held by Curtis Means, who was born at 21 weeks and 1 day back on July 5, 2020, at the University of Alabama at Birmingham’s Women and Infants Center, according to Guinness World Records.