Babies born through IVF are almost three times as likely to develop cancer in childhood, a study has found.
Experts say this might be due to eggs being fertilised by potentially defective sperm grown in a lab – rather than the fastest and strongest reaching them by natural selection.
Hormones used in IVF could also affect the foetus during a critical period of growth, increasing the baby’s risk of cancer. The Israeli research team behind the findings say problems that cause parents’ infertility in the first place may equally to blame.
But they raise concerns over the health implications for babies, with more than five million now having been born through IVF since the first in 1978. The long-term effects of the procedure are yet to be fully understood.
Lead author Professor Eyal Sheiner, from Ben-Gurion University of the Negev, said: "The research concludes the association between IVF and total paediatric neoplasms [tumours] and malignancies is significant.With increasing numbers of offspring conceived after fertility treatments, it is important to follow up on their health."
The study, published in the American Journal of Obstetrics & Gynaecology, looked at 242 187 newborn infants – of whom 1.1 percent were conceived via IVF.
It found 1.5 in 1 000 children born through IVF were diagnosed with a tumour after around a decade of being monitored – compared to 0.59 per 1 000 conceived naturally.