In 2002, two proud and relieved parents, Mr and Mrs A, saw their newborn twins for the first time, conceived after a long and difficult course of IVF treatment. At last it all seemed worthwhile. Except the babies were of mixed race, while both parents were white.
The IVF clinic had blundered, and used the wrong sperm to fertilise Mrs A鈥檚 eggs. The child鈥檚 biological father was Mr B, a man the couple had never met and who with his partner was also trying for a family using IVF. Similar accidents have happened in the US and the Netherlands.
Now, in a bid to stop such mistakes happening again, the UK鈥檚 regulatory body, the Human Fertilisation and Embryology Authority (HFEA) is considering labelling all embryos, eggs and sperm with barcodes or electronic ID tags. The idea, discussed at the HFEA鈥檚 annual conference in London last month, is that an alarm will sound if the wrong eggs and sperm are brought close to one another, for instance, or if a doctor attempts to collect the wrong embryo to implant into a mother-to-be.
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In June 2004, an independent report commissioned by the UK鈥檚 chief medical officer suggested clinics use a system of double-witnessing, which requires an embryologist to ask a colleague to witness and document every procedure in which an error could occur. But with 25 such procedures required for each round of IVF, the system is laborious. And it still leaves room for human error.
Sounding alarms
Steve Troup, an embryologist on the HFEA鈥檚 advisory group on safety and new technologies, is looking into alternatives. Barcoding has been used for more than a decade in the UK鈥檚 blood transfusion service, where it has slashed the error rate. Now IMT International, in Chester, UK, is developing barcodes for IVF procedures.
Digital cameras built into the IVF clinic鈥檚 benches read the barcodes off the bottom of labelled dishes containing eggs. A computer then reads the codes, and sounds an alarm if they do not match with the patient. 鈥淥ur system is incredibly safe,鈥� says Tim Haywood, director of IMT International.
The electronic tags, known as RFID tags, work in a similar way. They can be placed on the bottom of a dish containing an embryo, and are activated by radio waves which transmit across a clinic鈥檚 designated work areas. When activated, RFID tags respond by transmitting a unique ID code. 鈥淚f the samples don鈥檛 match [the patient], or you bring together two things that shouldn鈥檛 be in the same work area, the alarms will sound,鈥� Troup says.
The HFEA is investigating whether such a system would be safe, as there are concerns that radio waves might harm embryos. IVF Witness, an RFID system being developed by Research Instruments, in Falmouth, UK, has been tested on mouse embryos. The embryos are placed in Petri dishes which have tags attached to the bottom, and placed in an incubator with an antenna that activates the tags.
Low frequency
In Research Instruments鈥� tests, the tags transmitted continuously for four days without any perceptible effect on the embryos. Though the tests are not complete, 鈥渋t looks very, very good that there鈥檚 going to be no problem with it,鈥� David Lansdowne, technical director at the company told 快猫短视频.
Troup鈥檚 personal view is that RFID tags will be safe for in vitro procedures. The tags only transmit when activated by an external signal. And they work at the low frequency of 13.5 megahertz compared with 900 to 1900 megahertz used by cellphones.
The advisory group will need to be satisfied that such an RFID system would not significantly heat up an embryo, or cause other as-yet-unknown problems. Troup鈥檚 research team at the University of Liverpool, together with researchers at the University of Manchester, will be carrying out more work looking at the effect of radio waves on mouse embryos. Lansdowne says his team will be measuring the field strength from the RFID tags when the embryos are being worked on, and comparing this with background levels of radio waves.
