Couple expecting 'donor' baby

The Whitakers are expecting their third child

The British couple refused permission to select a baby to help their four-year-old son are now expecting a child.

Michelle Whitaker has become pregnant after undergoing IVF treatment in the United States in October.

Doctors in Chicago implanted two embryos, which had been screened to make sure they were a match for four-year-old Charlie.

I can't stop smiling

Michelle Whitaker

Charlie suffers from a type of rare anaemia which increases his chance of cancer or perhaps other fatal complications.

Cell transplant

He could be cured by a transplant of special cells from the new baby's umbilical cord - as long as the baby's tissue was a near-perfect match.

However, under normal conditions, only a small proportion of embryos conceived naturally or created through conventional IVF would be a match.

This would mean that the couple might have to have several further children before one matching Charlie was created.

The Whitakers applied for permission earlier this year to allow IVF doctors in the UK to select an embryo that provided a perfect match for Charlie.

However, regulators refused permission on technical grounds.

Charlie has a rare type of anaemia

The Human Fertilisation and Embryology Authority (HFEA) ruled that while it was acceptable to test and select embryos to prevent the birth of a baby with a genetic disease, it was not ethically acceptable to select them in order to help another child.

This prompted Michelle and her husband Jayson, from Bicester in Oxfordshire, to travel to the US to undergo the initial treatment.

Mrs Whitaker, 30, will find out later this week whether she is expecting twins.

Charlie's disease affects only 50 children in the UK. He currently needs blood transfusions every three weeks and painful injections almost daily just to keep him alive.

Even if the new baby is a match, there is only a tiny chance that it will develop Charlie's illness.

The umbilical cord contains a type of primitive cell called a stem cell which could help "kick start" Charlie's body into producing the red blood cells he needs.

The cells would be infused into him in a similar fashion to a bone marrow transplant.

Mrs Whitaker told the Daily Mail that the couple were overjoyed with the pregnancy.

"I can't stop smiling," she told the BBC.

Mr Whitaker added: "All that matters is it's a baby and it's right and it's going to help us save Charlie."