Cancer Risk among Children Born after Assisted Conception

Abstract

Study question: Are children, aged 0-14 years, born after assisted reproductive therapies (ART) in Great Britain between 1992-2008, at increased risk of childhood cancer in comparison to the general population?; A population based linkage study between the Human Fertilisation & Embryology Authority (HFEA) and the UK National Registry of Childhood Tumours (NRCT). Summary answer: In this internationally unique study there was no overall increased risk of cancer in British children born after assisted conception over the 17 year period. Increased risks were found for the development of hepatoblastoma and rhabdomyosarcoma though these were based on small numbers and absolute excess risks were small. What is knownalready: Large datasets are required to adequately investigate rare health outcomes in children born after assisted conception. The possibility of an increased cancer risk in this population has been suggested by the discovery of altered epigenetic patterns in assisted conception embryos, cord blood and placenta. Such altered epigenetic patterns have been implicated in carcinogenesis. The largest population-based study published to date (n = 26,692) found a small but significantly increased cancer risk compared to spontaneously conceived children. Study design, size, duration: In this population based linkage study, HFEA records of all 106,381 children born after assisted conception in Great Britain from 1992 to 2008 were linked to NRCT records in order determine the number of children who subsequently developed cancer. The average duration of follow up was 6.6 years. Participants/materials, setting, methods: UK law mandates reporting of all ART births to theHFEAand cancers in children under 15 years toNRCT, ensuring complete population coverage. Once databases were linked, cohort cancer rates were compared with population rates, stratifying for potential mediating factors including birthweight, multiple births, ART type and infertility cause. Main results and the role of chance: A total of 106,013 children, born after assisted conception, contributed 700,705 person years of observation. Overall, 108 cancers were identified compared to 109.7 expected (SIR- 0.98, 95% CI 0.81-1.19,p = 0.871). Significantly morechildren developed hepatic tumors than expected (6 vs. 1.83, SIR- 3.27, 95% CI 1.20-7.12, p = 0.029, AER= 5.94 per million person years at risk). This excess risk was associated with low birth weight (for children with a birth weight <2500g SIR=…