Study debunks the idea that children born through assisted reproductive technology are more prone to cancer
Children born after assisted reproductive technology (ART) do not appear to be at greater risk of developing cancer than other children. This is the conclusion of the first study to look at the long-term cancer risk in ART children compared to those in the general population.
The study of 47,690 children has been published in Human Reproduction, one of the world’s leading reproductive medicine journals. It is important because, until now, there has been conflicting evidence about whether or not ART children have an increased risk of cancer. The children in this study were followed for a median average of 21 years, which makes it the first study to compare outcomes in these children over such a long period of time.
Lead researcher, Professor Flora van Leeuwen, Head of the Department of Epidemiology in The Netherlands Cancer Institute, Amsterdam (The Netherlands), said: “This study, with a median follow-up of 21 years, is especially important because it includes a comparison group of naturally conceived children born to subfertile women; these women are different from the general population and it is possible that difficulty in conceiving could be a factor that influences the risk of cancer in their offspring.”
“It could be that some fertility treatments might induce heritable alterations in certain genes that increase the risk of melanoma and leukaemia; however, more research with larger numbers is needed to clarify this finding.”
The first author of the study, Ms Mandy Spaan, a PhD student in the Department of Epidemiology, said: “We found that of the 47,690 children included in the analysis, 231 developed cancer. After adjusting for factors that could confound the results such as age and the parental cause of subfertility, the overall long-term risk for cancer was neither increased in the ART-conceived children compared with naturally conceived children from subfertile women, nor when compared with the general population.”
“However, cancer risk was somewhat increased, although not statistically significantly so, in children conceived after intracytoplasmic sperm injection [ICSI] or from embryos that had been frozen before being thawed and used for fertility treatment. These are two types of fertility treatments that are used more often nowadays. We also found a slightly increased, statistically insignificant risk of lymphoblastic leukaemia and melanoma. As the numbers of cancers in these groups were small, these findings may be due to chance and must be interpreted with caution.”
Of the 47,690 children born alive, 24,269 were conceived by ART, 13,761 were naturally conceived and 9,660 were conceived naturally or with the help of fertility drugs, such as ovarian stimulation medication, but not by ART.
Of the 231 cases of cancer occurring among all the offspring, there were 31 cases of lymphoblastic leukaemia and 26 cases of melanoma.
Ms Spaan said: “There is no clear explanation for why there should be higher numbers of these cancers. It could be that some fertility treatments might induce heritable alterations in certain genes that increase the risk of melanoma and leukaemia; however, more research with larger numbers is needed to clarify this finding.”
