May 2, 2024

expert reaction to study looking at medically assisted reproduction and risk of cancer among offspring

A study published in JAMA Network Open looks at medically assisted reproduction and cancer risk. 

Rachel Cutting, HFEA Director of Compliance and Information, said:

“HFEA data shows that over 390,000 children were born as a result of fertility treatment in the UK between 1991 and 2021. This study is reassuring as the results show that the risk of Leukaemia for children born after assisted reproduction did not differ significantly from that of children conceived naturally.

“Health outcomes in children conceived using Assisted Reproductive Technology is a high priority for the HFEA and we provide high-quality information for patients and professionals using the new and emerging research we monitor. Anyone considering fertility treatment can access this, and other impartial information on fertility treatments and UK licenced clinics at www.hfea.gov.uk.”

Dr Channa Jayasena, Reader in Reproductive Endocrinology, Imperial College London, said:

“The authors have conducted a population study suggesting that children conceived using fertility treatment have higher than normal risks of leukaemia. My main criticism is that the results do not appear corrected for parental age. Couples having a baby naturally are more likely to be younger and fitter than couples needing fertility treatment. We know that the health of both mum and dad can affect outcomes of pregnancy. In particular, increased age reduces egg and sperm quality by causing DNA damage. It is already known that older mums and dads are slightly more likely to have children with leukaemia, just as with Down’s syndrome. However, the vast majority of children born following fertility treatment are healthy. Shifts in society mean that more women need to secure employment stability before having kids. In my opinion, merely telling women to have kids earlier is unhelpful medical advice. Instead, we should focus on reducing modifiable risk factors for childhood leukaemia, such as smoking.”

Dr Richard Francis, Deputy Director of Research at Blood Cancer UK, said:

“Childhood leukaemia is a form of blood cancer, which is fast growing and needs urgent treatment. However, while leukaemia can be a life-threatening illness the outcomes for children with leukaemia are improving all the time as researchers find more effective and kinder blood cancer treatments.

“The findings in this well-conducted yet limited study suggest children born after two forms of assisted conception had an increased risk of leukaemia compared with children conceived naturally. Findings from this one study must be treated with caution particularly as this was conducted in a different healthcare system from our own, and where the number of children with blood cancer is very small. Importantly this study can’t prove a direct cause between mechanically assisted conception and blood cancer risk.

“The message to anyone who has been diagnosed with any blood cancer is this: it is not your fault. Risk factors are not the same as causes and there are various risk factors for blood cancer that all interlink, with things like your age, sex and ethnicity playing an important role too.

“It’s important to remember that the risk for children developing leukaemia remains low. For those going through, or who have a young child from assisted conception these findings shouldn’t be something to worry about but if you do have any concerns you should reach out to your healthcare team. Alternatively, you can contact our support line on 0808 2080 888. For further information please visit https://bloodcancer.org.uk/understanding-blood-cancer/what-causes-blood-cancer/”

Prof Alastair G Sutcliffe, Professor of General Paediatrics, UCL and Great Ormond Street Institute of Child Health, said:

“This is a French wide study of all French children in the mother child registry. As the info was collected independent of the grounds for the registry it is likely to be reliable and unbiased.

“The study suggests a slight increase in total (absolute numbers) of children diagnosed with leukaemia when conceived with ART (Frozen thawed embryos and to a lesser degree fresh embryo transfer), however overall cancer risk is similar to the naturally conceived children.

“This is overall consistent with other studies of ART conceived children with overall no increase or very slight increases in absolute numbers.

“They have not accounted for family history or subfertility history in the controls. This is an association and not causation study. Implications are continued monitoring.

Professor Sir Mel Greaves, Institute of Cancer Research, London, said:

“A statistically significant association between reproduction via embryo transfer and subsequent risk of acute lymphoblastic leukaemia (ALL) in offspring, as reported by Rios et al., may or may not reflect a causal link. Potential confounders related to known peri-natal risk factors for ALL should be considered. These include C -section birth, lack of, or minimal, breast feeding and lack of older siblings.”

‘Medically Assisted Reproduction and Risk of Cancer Among Offspring by Paula Rios et al. was published in JAMA Network Open at 16:00 UK time on Thursday May 2nd. 

DOI: 10.1001/jamanetworkopen.2024.9429

Declared interests

Dr Jayasena: No conflicts.

Dr Francis: No conflicts of interest.

Prof Sutcliffe: I am involved in an international study looking at cancer risk after MAR conventionally called ART.

For all other experts, no reply to our request for DOIs was received.