A British mother is calling her baby boy a ‘miracle’ after he grew outside of her womb and survived.

Jayne Jones, 38, was 27 weeks pregnant when a routine ultra-sound revealed that her baby was growing in her abdomen, the U.K.’s Daily Telegraph reports.

It’s one of the rarest forms of ectopic pregnancy and almost all such fetuses die within weeks — even days— of conception, according to the report.

Ten days after the ultra-sound, Jones underwent a ground-breaking surgery that had never been done in Britain before.

It took a team of 36 doctors and a procedure known as a laparotomy – which opens the abdomen — to safely deliver little Billy who weighed in at 2 pounds, 2 ounces, the Telegraph reported.

Following the surgery, Billy was immediately placed in an incubator.

"He was so tiny,” Jones told the newspaper. “He was in a little resealable sandwich bag to keep his temperature up. They told me that, for all the millions spent on the NICU, what's made the biggest difference to survival rates are Tesco resealable sandwich bags.”

Now, nearly 5 months later, Jones and her little boy are doing just fine.

Click here to read more from the Daily Telegraph.