Children conceived through in vitro fertilisation (IVF) have a slightly increased risk of being diagnosed with cancer during their first decade of life compared with children conceived naturally, a study* published in JAMA Pediatrics has found.
Researchers from the University of Minnesota conducted the largest study of childhood cancer after conception by IVF to date. They linked records of live births reported to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System between 2004 and 2013 to the birth and cancer registries of 14 states, comprising 66% of births in the United States and 75% of IVF-conceived births. These records were then linked to the cancer registries of the same states to find cancers diagnosed between 2013 and 2015. Researchers then randomly selected 10 children conceived naturally for each child conceived by IVF. The final dataset consisted of 275,686 IVF children and 2,266,847 naturally conceived children.
Among the children included in the study, 321 cancers were detected among the children conceived by IVF and 2,042 cancers were detected among the children not conceived by IVF.
Analysis of the data revealed that the overall cancer rate of IVF children (per 1,000,000 children) was about 17% higher than that of non-IVF children, and the rate of hepatic tumours was over 2.5 times higher among IVF children than non-IVF children. The rates of other specific cancers did not differ between the two groups, and there were no associations of childhood cancer with specific IVF treatment techniques.
"The most important takeaway from our research is that most childhood cancers are not more frequent in children conceived by IVF," said Logan Spector, a professor in the Medical School and Masonic Cancer Center member.
"There may be an increased risk of one class of cancers in children; however, due to the nature of our study, we could not distinguish between IVF itself versus the parents' underlying infertility. Overall, these results are reassuring to parents who've had children through IVF."
Dr Jane Stewart, chair of the British Fertility Society said: “This study suggests that following up on the health of IVF babies over time is a useful exercise. It does not, however, suggest that IVF causes these cancers.
“The research involved a large cohort, which improves reliability, but the researchers were not able to consider other factors that might lead to childhood cancers in this group.
“As with other similar studies, an association between IVF and cancer is found but it is impossible to say what the cause is. We still need to know whether it is the treatment itself or the underlying infertility that accounts for this difference. There are also lifestyle and other factors that could contribute to cancers in this group, which are not explored in the paper.”
*Spector LG, Brown MB, Wantman E, et al. Association of In Vitro Fertilization With Childhood Cancer in the United States. JAMA Pediatr. Published online April 01, 2019. doi:10.1001/jamapediatrics.2019.0392