IVF babies have 17% higher risk of cancer
CHILDREN born using IVF may be at greater risk of cancer, research suggests.
Scientists found babies conceived via fertility treatment to be 17 per cent more likely to have the disease by the age of five.
Experts stressed that although the relative risk was higher, it was still tiny in absolute terms. Among 20,000 babies born through IVF in Britain each year, only two to three extra cancer cases would be expected.
But fertility experts said couples considering IVF should be made aware of the risk in light of the findings, however marginal.
Scientists are divided as to whether the extra risk is caused by IVF itself or a result of underlying problems linked to the mother’s infertility and then passed on to the child.
The researchers from the University of Minnesota studied 275,700 children conceived via IVF and compared them with 2.3million children conceived naturally.
A rare strain of liver cancer, called hepatoblastoma, was the most common kind seen among IVF children, the researchers said. Writing in the journal JAMA Pediatrics, they said: ‘We found, at most, a small, marginally significant association between IVF and overall cancer in childhood.
‘We cannot attribute the observed small elevated risks to IVF itself rather than the underlying causes of infertility.’
Some scientists believe the chemicals in which embryos are fertilised and manipulated before being implanted in the womb may be to blame. Professor Alastair Sutcliffe, of University College London, said: ‘The authors are right in calling for further studies as cases accumulate in the at-risk population.’
He added: ‘It is indeed plausible that this slight increase in hepatoblastoma is an effect of IVF process rather than the genetic nature of sub fertility.’
Other researchers said genes that cause infertility also raise the risk of liver cancer. These may be passed on genetically from mother to child.
The women in the study who underwent IVF were also five to six years older on average than those who conceived naturally – another possible cause of cancer in children. Dr Anindita Roy, of the University of Oxford, said: ‘ It is important to note that the increased risk of cancers might be due to other confounding factors that differ between IVF and non-IVF children, such as congenital anomalies, certain syndromes, and maternal causes for infertility that can also lead to inherited causes of cancer predisposition.’
Dr Jane Stewart, chairman of the British Fertility Society, said: ‘As with other similar studies, an association between IVF and cancer is found but it is impossible to say what the cause is.’