'Chances slim' for Siamese twins

The twins share a heart and a liver

Doctors treating the twin babies who share one heart have decided not to attempt to separate them immediately.

The surgeon in charge of the case says that the chances of a successful operation are very small.

In their current state the chances of a successful outcome are very slim

Professor Lewis Spitz, Great Ormond Street Hospital

Without an operation, both twins will certainly die, and it is possible this could happen in the next few months.

Professor Lewis Spitz, a world expert in twin separation at Great Ormond Street Hospital, London, said that the repair of the complex maze of blood vessels surrounding the heart was "virtually impossible."

Construction of a heart to sustain even one baby would be equally difficult, he said.

No babies in the same situation have ever survived long-term.

He said: "In their current state the chances of a successful outcome are very slim.

"However, if the twins survive for a few months and remain in a stable condition - something that is also uncertain - we may review the situation."

Support

He added: "This is an extremely difficult decision and we are doing everything we can to support family during this very distressing time."

He told the BBC that at one stage early in pregnancy, the medical team had been optimistic that separation could be attempted, but that later scans had painted a bleaker picture.

Professor Spitz: Operation "virtually impossible"

It had been hoped that by sacrificing her sister Courtney, that Natasha Smith could be saved.

It was revealed that the hospital has decided, should an operation become a reality, to go to the High Court to confirm its legality.

Parents Tina May and Dennis Smith are supportive of the doctor's decision. They are said to be "coping well" with the news.

Breathing difficulties

Natasha and Courtney were born at Queen Charlotte's and Chelsea Hospital, west London, on Monday, joined from the belly button to the top of the chest.

There are already reports that the twins are weakened by breathing difficulties.

They are currently in intensive care, where doctors are supplying oxygen and attempting to feed them.

It is unlikely that the heart they share will be able to support them both for much longer, particularly as it also has a substantial hole in one of the chambers.

Complex

The blood vessels which supply each twin are also intertwined in a highly complex way, increasing the difficulty of any operation to separate them.

Experts are doubtful whether the structure could be adapted to form a single, viable heart for Natasha.

Natasha and Courtney Smith just hours after their birth

Tina and Dennis, who also have an 11-month-old son called Damien, discovered they were expecting conjoined twins following a routine scan in November, but as a Catholic, Ms May was against having an abortion on religious grounds.

She said of the birth: "My happiness is tinged with the agony of knowing the ordeal that lies ahead for us all."

The heart the twins share is mainly in the body of Natasha. They also share a liver.

Conjoined twins occur in about one in 100,000 pregnancies and only about 19 sets have been dealt with at British hospitals since 1984.

Around 40% of conjoined twins are joined at the chest. It is rare to have only a single heart, but there are frequently heart problems in conjoined twins.