IVF samples to be tagged after hospital mixes up embryos

A London hospital is using electronic "tags" to identify IVF samples after doctors used the wrong sperm in fertility treatment.

Guy's hospital said today that it had ordered the tracking devices to prevent further mistakes. The mix-up occurred this year and involved three couples undergoing IVF at the hospital's assisted conception unit.

Fertility doctors discovered the mistake and destroyed the embryos before they were implanted. Experts say mistakes are rare but raise concerns about the treatment of thousands of couples who seek fertility treatment every year.

In 2002 a white British couple gave birth to black twins after a blunder at an IVF clinic. The parents had to go to the High Court for a judge to decide the legal status of the babies.

The electronic tagging system commissioned by Guy's uses radio frequency to track sperm samples and eggs through the fertilisation process to ensure mothers do not get impregnated with the wrong embryo.

A chip is attached to the bottom of every Petri dish and test tube which contain the patient's sample. The doctor passes the container over a scanner in the laboratory before fertility treatment takes place.

A computer next to the scanner acts as an early warning system by flashing a "stop" message on screen if the tag's details do not match those of the patient. The tag also sets off an alarm if samples from different parents are brought into the same area in the laboratory.

Any mismatches identified by staff are immediately logged and investigated.

At least three other fertility clinics in the South-East are already using IVF tracking.

Guy's and St Thomas NHS Foundation Trust said it took the decision to invest in the electronic sperm and egg tracking to avoid further errors.

A spokeswoman said: "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. We have now ordered in a tagging system to prevent this happening again."

Fertility watchdog the Human Fertilisation and Embryology Authority warned embryologists at Guy's and St Thomas' in 2007 that they were at risk of confusing men's sperm samples.

Doctors at the hospital also implanted a woman with a "weak" embryo by mistake despite the fact they had successfully produced stronger embryos for treatment.

The medical staff discovered the mistake only after treatment had taken place and after the woman's pregnancy failed.