A mother has told how her twin children were born an incredible nine days apart.

Ian and Laia – now 10 months old – were born in Sant Joan de Deu Hospital in Rubi -near Barcelona, Spain – on 17th January and 26th January.

They were “very premature” – said parents Laura Pupo and Jose Carlos Martins – with Ian born at 28 weeks and three days and Laia at 29 weeks and five days.

Each newborn weighed just over one kilogramme (2 lb 3 oz).

The children were born in a rare delivery known as asynchronous birth.

Laura told Spanish media: “It was shocking, I had never heard of it before.”

She explained: “The children are in two sacs, there are two placentas, their vital support inside the belly is independent and can act as if they were two different pregnancies.”

Laura recalled the moment when Ian was born extremely prematurely. She said: “I only remember she [the nurse] told me, ‘He’s alive, he’s alive.'”

Ian was transferred to an incubator, but medics held off from delivering Laia because, according to Laura: “I was the best incubator for her to continue developing”.

Laia was born nine days later.

Despite being born 90 days premature, both Ian and his sister are now healthy and did not suffer any lasting complications.

Laura said: “I’m surrounded by a medical family and they saw it as a novelty.

“The midwife told me she had been working for 30 years and that she had not heard of an asynchronous delivery before.

“For those who are engaged in this, it was also something new.”