Concerns have been raised that children born after fertility treatment are at greater risk of complications, congential malformations and infertility problems themselves but this is the first time a significant association with cancer has been found.
The problems are not thought to be linked to the procedure itself rather they are more likely to be a result of the infertility itself or complications that occur around birth such as prematurity and low birth weight which are linked to fertility treatment.
Swedish researchers used records of more than 26,000 children born after IVF treatment and linked them to registers of cancer diagnosis.
They found 53 children developed cancer, ranging from a very young age, up to 19-years-old, against an expected number of 38.
The team said this meant there was a 42 per cent increased risk of childhood cancer in these children.
The cancers included leukaemia, cancers of the eye and nervous system, solid tumours and six cases of a condition called Langerhans histiocytosis. There is debate over whether this condition is a real cancer or not but even when these cases were excluded the increased risk of cancer was still 34 per cent, the researchers said.
IVF-conceived children were 87 per cent more likely to have received a diagnosis of cancer by the age of three than the general population.
After this age the risk of cancer in IVF children reduced.
The study found that seven of the 53 children with cancer also had other problems including malformations and Down’s Syndrome which are known to have a strong link to cancer.
The findings are published in the journal Pediatrics.
Lead author Bengt Källén, of the University of Lund in Sweden, wrote in the journal: “We found a moderately increased risk for cancer in children who were conceived by IVF.
“This is probably not attributable to the IVF procedure itself but could be an effect of confounding from unidentified characteristics of women who undergo IVF or could act via the widely known increased risks for neonatal complication.
“It should be stressed that the individual risk for a child who is born after IVF to develop childhood cancer is low. Additional studies on large populations are needed to permit analysis of such a rare outcome as cancer and notably of specific types.”
There are around 1,700 children diagnosed with cancer before the age of 15 in Britain each year and survival rates are generally good.
Three quarters of children live for a further five years after diagnosis and the vast majority of these are considered ‘cured’.
Leukaemia is the most common form of childhood cancer in Britain
By Rebecca Smith, Medical Editor