A High Court judge has named the hospital where a white woman gave birth to mixed race twins after a mistake at an IVF clinic.

Dame Elizabeth Butler Sloss, head of the family division at the High Court, has ruled Leeds General Infirmary can now be identified as the fertility clinic that carried out the fertility treatment.

The Trust unreservedly apologises to all those affected

Leeds Teaching Hospitals NHS Trust statement

Two couples, one white and one black, underwent treatment at the clinic.

Genetic tests established that the white woman who gave birth to the mixed race twins was their biological mother, but that her eggs had been fertilised with the wrong sperm.

An internal hospital inquiry suggested that the mistake probably occurred either when the samples of sperm were placed in a centrifuge or when they were removed from a storage box immediately before being injected.

The mix-up intensified concerns over the safety of procedures at IVF clinics and the way they operate.

Experts have insisted that mix-ups involving embryos are rare - and never exceed two a year out of thousands of cycles of IVF.

But the Human Fertilisation and Embryology Authority (HFEA) is beefing up its rules to try to minimise the risk still further.

Drugs

A spokesman for Leeds General Infirmary said: "The Leeds Teaching Hospitals NHS Trust deeply regrets the anguish suffered by all those affected by the error that occurred within the Assisted Conception Unit at the General Infirmary in Leeds.

"The Trust unreservedly apologises to all those affected."

Restrictions have been placed on the clinic's licence by the HFEA.

The black couple involved in the mix-up are still childless, Dame Elizabeth revealed.

But she said no-one was suggesting that the twins should be uprooted from their "happy and loving" environment with the white couple, Mr and Mrs A.

There is always going to be the possibility of mistakes

Suzi Leather

Dame Elizabeth added that the next stage in the proceedings, to establish the legal parentage of the twins, will take place early next year.

She said the impact of the 1990 Human Fertilisation and Embryology Act and the 1998 Human Rights Act would be considered in the complex case which was "unprecedented" in the UK.

No further details about the identity of the couples or the children can be revealed, Dame Elizabeth ruled.

She added that there was no evidence of any other patients receiving the wrong embryos at the Leeds clinic.

Last week it was revealed that a further IVF blunder at St George's Hospital, London, left two women with the wrong embryos put back into their wombs.

Both required medical procedures and drugs to prevent pregnancy.

Mistakes rare

Suzi Leather, HFEA chair, told the BBC: "Clearly it is imperative that the right sperm are mixed with the right eggs, and the right embryos are put back in the right women.

"This is an area which is acutely sensitive and the repercussions of mistakes are enormous - it is not like going on holiday and being put in the wrong hotel."

She said embryo mix-ups were extremely rare events, but added: "The fact that this case, which we know about, has involved mixed race babies suggests that it might not be the only time this has ever happened."

Steps, including beefing up HFEA regulations to insist, rather than recommend, two people should witness all procedures during IVF treatment, have been put in place since the incident.

The HFEA is also considering whether each clinic should appoint someone to have overall control for the quality of the service it provides.

Ms Leather said serious mistakes were only made in less than one tenth of a percent of all cases.

Since the HFEA was established in 1991, 65,000 babies have been born after IVF treatments.

But she said: "You cannot entirely rule out human error. There is always going to be the possibility of mistakes."

Responsible

Dr Simon Fischel, an IVF expert and an inspector for the HFEA, said all those working in IVF clinics were aware "they are carrying a new human life in their hands."

He added: "However good the regulation system, however consistent the practice, you can't 100% guarantee that there will never be a human error.

"But you can guarantee that everyone will do their professional and responsible best to ensure mistakes do not happen."

Two helplines have been set up for worried parents.

Leeds General Infirmary can be contacted on 01924 889689.

People who are not patients at that hospital can call NHS Direct for advice on 0845 4647.