New York: While pregnancies enabled by in vitro fertilisation (IVF) have faced more difficulties, with children born earlier and smaller, according to a new study, they may also raise risk of cancer in babies. IVF is associated with birth defects and imprinting disorders. Because these conditions are associated with an increased risk of childhood cancer, many of which originate in utero, descriptions of cancers among children conceived via IVF are imperative, said researchers from the University of Minnesota in the US. The study, published in JAMA Pediatrics journal, found that the overall cancer rate among IVF children was about 17 per cent higher than non-IVF children. In addition, the rate of liver tumours was over 2.5 times higher among IVF children than naturally conceived children. However, there was no difference in the rates of other cancers between the two groups. "The most important takeaway from our research is that most childhood cancers are not more frequent in children conceived by IVF," said Logan Spector, Professor at the University of Minnesota in the US. "There may be an increased risk of one class of cancers in children. However, due to the nature of our study, we could not distinguish between IVF itself versus the parents' underlying infertility," he said. The study consisted of 275,686 IVF children and 2,266,847 naturally conceived children. While the study found a link between IVF and childhood cancer, it's important to note that this does not suggest IVF causes cancer, the Mirror.co.uk reported "An association between IVF and cancer is found but it is impossible to say what the cause is," Jane Stewart, Chair of the British Fertility Society, was quoted as saying. "We still need to know whether it is the treatment itself or the underlying infertility that accounts for this difference. "There are also lifestyle and other factors that could contribute to cancers in this group, which are not explored in the paper," Stewart said.