The risk of congenital malformations is increased in children born through assisted reproductive technology (ART), such as IVF (in vitro fertilisation)or ICSI (intracytoplasmic sperm injection), researchers report today at the annual conference of the European Society of Human Genetics.

In the largest study to date, researchers in France surveyed parents and paediatricians from 33 ART-registered clinics - approximately one third of the registered centres in France. Every ART birth from these clinics, from 2003 to 2007, was included in the study - a total of 15,162 births. Data was compared with information from national birth registers.

Lead researcher Dr Christine Viot said: 'We found a major congenital malformation in 4.24 per cent of the children…compared with the two to three per cent that we had expected from previous published studies. This higher rate was due in part to an excess of heart diseases and malformations of the urogenital system. This was much more common in boys. Among the minor malformations, we found a five times higher rate of angioma, benign tumours made up of small blood vessels on or near the surface of the skin. These occurred more than twice as frequently in girls than boys'.

This risk was significantly lower than some findings from previous studies, which had estimated a risk of up to 11 per cent. Dr Viot said: 'Given that our study is the largest to date, we think that our data are more likely to be statistically representative of the true picture'.

It is not clear what factors are contributing to the higher risk of malformation in ART births. Dr Viot said: 'We need more research in order to understand the relationship between embryo culture media, timing of embryo transfer, the effects of ovarian stimulation, the use of ICSI, freezing of gametes and embryos, and these disorders'

Dr Viot continued: 'We estimate that in France some 200 000 children have been born after ART and therefore a malformation rate of this magnitude is a public health issue. It is important that all doctors and also politicians are informed about this'. She also stressed that the public should be informed about the higher risk of malformation associated with ART. She said that currently most ART clinics in France would only inform women undergoing fertility treatment about the risks of ART if they were specifically questioned.

The Human Fertilisation and Embryology Authority (HFEA) has issued a statement regarding the study, saying that 'the risks are still very small [but] it is important that patients are informed about this but not alarmed by it'. They added that 'where it suggests there may be a greater risk we share this information with patients in a clear way to help them understand the risks associated with the choices they are making'.

Infertility Network UK have also issued a statement: 'As with all medical procedures, patients need to be informed about all aspects of the treatment including possible risks to them, or in the case of assisted conception, the potential child. Patients who have any concerns should contact their clinician in the first instance to discuss them'.

Reproduced from BioNews with permission, a web- and email-based source of news, information and comment on assisted reproduction and human genetics, published by Progress Educational Trust.