BACKGROUND AND PURPOSE:

• Previous studies have suggested a possible link between children conceived with assisted reproductive technology (ART) and cancer risk
• Limitations include
  • Confounding due to underlying subfertility | Relatively short follow-up and/or small ‘n’
• Spaan et al. (Human Reproduction, 2019) evaluated cancer risk in ART-conceived children and young adults using Dutch OMEGA-offspring cohort

METHODS:

• Nationwide historical cohort study with prospective follow-up (1980-2001)
• Participants
  • All live-born offspring from women treated with subfertility treatments and followed in the OMEGA study
• Data sources
  • Medical records and questionnaires
  • Includes information on conception method of each child and potential confounders
  • Cancer incidence was ascertained through linkage with The Netherlands Cancer Registry
• Data analysis
  • Cancer risk in ART-conceived children was compared with risks in
    • Naturally conceived children from subfertile women (using hazard ratio [HRs])
    • The general population (standardized incidence ratio [SIRs])

RESULTS:

• 47,690 live-born children included
  • ART-conceived: 24,269
  • naturally conceived: 13,761
  • 9660 were conceived naturally or through fertility drugs (not ART)
• Follow-up
  • Median follow-up: 21 years (interquartile range (IQR): 17–25)
  • Follow-up was shorter in ART-conceived children (20 years) vs naturally conceived children (24 years)
• Overall cancer risk was not increased in ART-conceived children compared to
  • Naturally conceived children from subfertile women: HR 1.00 (95% CI, 0.72–1.38)
  • General population: SIR 1.11 (95% CI, 0.90–1.36)
  • Still not significant when analyzing data from from 18 years of age onwards
    • Cancer in ART-conceived vs naturally conceived individuals: HR 1.25 (95% CI, 0.73–2.13)
• Risks likewise not significant in children conceived by
  • ICSI: HR 1.52 (95% CI, 0.81–2.85)
  • Cryopreservation: 1.80 (95% CI, 0.65–4.95)
• Specific cancers in ART-conceived children were not associated with increased risk compared with naturally conceived children
  • Lymphoblastic leukemia: HR 2.44 (95% CI, 0.81–7.37)
  • Melanoma: H 1.86 (95% CI, 0.66–5.27)

CONCLUSION:

• While this study had a long median follow-up, the authors still suggest even longer follow-up to assess if there is any risk of cancer in adults and in children conceived by ICSI or cryopreserved embryos due to slightly elevated, although non-significant, risk
• The authors conclude

This large-scale study with 21 years of follow-up shows that overall cancer risk in ART-conceived children is not increased, neither when compared with the general population nor when compared with naturally conceived offspring born to subfertile women.

Learn More – Primary Sources:

Risk of cancer in children and young adults conceived by assisted reproductive technology

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