“I’ve been doing this almost 20 years… but I’ve never seen a baby this young be as strong as he was,” said Dr Brian Sims.

Curtis Means weighed only 420 grams at the time of birth.

A US boy who was born at only 21 weeks and one day has been certified as the world’s most premature baby to survive. When he was born in Alabama last year, Curtis Means weighed just 420 grams. Guinness World Records on Wednesday confirmed that Curtis, who is now a happy and healthy 16-month-old, set a new world record by defying -1% odds of survival.

“Born in July 2020, exactly one month after the previous world’s most premature baby, Curtis Zy-Keith Means from Alabama, USA, would go on to make history,” Guinness World Records said in a statement.

A full-term pregnancy is typically 280 days, while Curtis was delivered at a gestational age of 148 days, making him almost 19 weeks premature.

“The medical staff told me that they don’t normally keep babies at that age,” the boy’s mother, Michelle “Chelly” Butler, told Guinness in an interview. “It was very stressful.”

Despite being born 19 weeks premature, Curtis responded extraordinarily well to treatment, much to the surprise of doctors and staff at the University of Alabama Hospital. Curtis was given breathing support and medication for his heart and lungs to keep him alive. He was discharged after spending 275 days (about nine months) in the hospital. Unfortunately, his twin sister, C’Asya, did not respond to treatment as well as Curtis did. She died a day after birth.

Dr Brian Sims, the neonatologist on duty who oversaw the twins’ delivery, said: “The numbers say that babies at this age will not survive.”

Curtis still needs supplemental oxygen and a feeding tube, but doctors say he is doing well.

“I’ve been doing this almost 20 years… but I’ve never seen a baby this young be as strong as he was… There was something special about Curtis,” Dr Sims said.