An Alabama baby born at 21 weeks has been certified the most premature in the world

• A baby born at 21 weeks is the world's most premature baby to survive, Guinness World Records said.
• Curtis Zy-Keith Means was born in Alabama in July 2020, weighing 14.8 ounces (420 grams).

A baby born in Birmingham, Alabama, at 21 weeks and one day has been certified by Guinness World Records as the world's most premature baby.

Curtis Zy-Keith Means was born in July 2020. In a Wednesday statement, Guinness World Records said Means had broken a world record and was "certified as the world's most premature baby to survive."

He weighed 14.8 ounces (420 grams) at birth, which is the same as a soccer ball, Guinness World Records said.

That's seven times less than the weight of an average newborn who was brought to full term, Guinness World Records said.

His mother, Michelle, told Guinness World Records: "The medical staff told me that they don't normally keep babies at that age. It was very stressful."

He was kept on a ventilator for three months, and was able to go home after spending 275 days - just over nine months - in the hospital, Guinness World Records said.

He is now 16 months old and "thriving," Guinness World Records said, adding that he still needs to use supplemental oxygen and a feeding tube.

Means was born alongside a twin, C'Asya, who died a day after they were born.

They were born at the University of Alabama at Birmingham. Dr. Colm Travers, assistant professor at the university's neonatology division, told Guinness World Records: "Survival at this gestational age has never happened before, so before Curtis was born his chances of survival would have been far less than 1%."

Dr. Brian Sims, the neonatologist who oversaw the birth, told Guinness World Records: "I've been doing this almost 20 years ... but I've never seen a baby this young be as strong as he was."

The record was previously held by a baby born at 21 weeks and two days - one day longer than Means.