Children born after medically assisted procreation (ART) do not develop more cancer than others, except for leukemia where a very slight additional risk was observed, a large French study underlined on Friday. This study is one of the largest carried out to date on the subject and covers more than 8.5 million children born in France between 2010 and 2021.

Scientists from Inserm and the EPI-PHARE scientific interest group (ANSM/Cnam), joined by experts in medically assisted procreation (PMA), published their results in the journal JAMA Network Open. The idea was to compare the cancer risk of children conceived under assisted reproduction to that of children conceived naturally.

“PMA techniques are quite recent and many studies have so far shown quite heterogeneous results, it was necessary to supplement existing information,” indicates Rosemary Dray Spira, epidemiologist and deputy director at EPI-PHARE. The scientists used data from the National Health Data System.

Among the cohort followed, up to a median age of 6.7 years, were 260,236 children (3%) conceived by AMP. During this follow-up, 9256 children including 292 children conceived by AMP developed cancer. The risk of cancer, all types combined, was not higher in these children than in those conceived naturally, the study notes.

However, “a slight increase in the risk of leukemia has been observed” in children conceived via in vitro fertilization (IVF). “Out of 20,000 children between 0 and 10 years old, approximately 10 will have leukemia in the general population; according to our estimate, for children born by IVF, we will have between 13 and 14, the additional risk is therefore very rare,” underlined Ms. Dray Spira.

For comparison, the risk of infant mortality is higher for all babies: 74 deaths are recorded for 20,000 births. For the moment, scientists are not able to explain whether the slight increase observed is “linked to the ART techniques themselves, to parental infertility factors or to the combination of the two”, recognized Patricia Fauque, head of the Dijon AMP Center.

Identifying the mechanisms underlying this increase will need to be the subject of further research, the researchers acknowledged. “Our concern is to understand better and better the determinants of the occurrence of these cancers,” said Jacqueline Clavel, Inserm research director.