A spokesman for the clinic said that 'We identified potential problems with the eggs and sperm of three couples. All were notified of the issue and offered counselling and an additional cycle of treatment. No embryos were transferred. This was an unfortunate and one-off incident'.
However, according to the Sunday Times, another mix up occurred at the clinic in 2007 - a poor quality embryo was implanted in a patient even though another, more healthy one was available, and the pregnancy failed. The clinic at Guy's and St Thomas' has now ordered a new tagging system to track all IVF samples. Similar systems are already in use in at least three clinics in England.
The Human Fertilisation and Embryology Authority (HFEA) reportedly warned the hospital in 2007 that preparing multiple different sperm samples in the same area carried a risk of mixing them up. The HFEA says that such serious problems occur only 0.04 per cent of the time, but that it is impossible to entirely eradicate human error.
Sue Avery, consultant embryologist at Birmingham Women's Hospital and a former chairwoman of the Association of Clinical Embryologists, said the sperm mix-ups at Guy's were very serious and that 'we would expect in the case of repetition that the HFEA might want to investigate unless they can be thoroughly satisfied that the centre has taken sufficient action'. The HFEA replied that it takes such incidents very seriously. 'When incidents are reported to us, we will investigate and take action where necessary. The risk of mix-ups is a serious concern for patients, clinics and the HFEA'.
In 2002, following a mix-up of IVF embryos a white couple in Leeds gave birth to black twins, and they had to resort to legal action to determine to whom the babies belonged. The Sunday Times report also mentioned two other 2007 cases in which couples received the wrong embryos, which were not made public at the time.