Thyroid cancer: what is the appropriate interval between RAI and pregnancy?

  • Kim HO & al.
  • JAMA Intern Med
  • 21 Oct 2019

  • curated by Brian Richardson, PhD
  • Univadis Clinical Summaries
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Takeaway

  • Treatment with radioactive iodine (RAI) after thyroidectomy for thyroid cancer is not associated with adverse pregnancy outcomes when conception occurs ≥6 months after treatment.

Why this matters

  • Current guidelines recommend a delay of 6-12 months, but no large-scale study had previously analyzed outcomes.

Key results

  • The pregnancy rate during the study was 9.7%.
  • Overall, pregnancy outcomes were similar between patients who underwent surgery alone and patients who underwent surgery and RAI:
    • 30.7% vs 32.1% for abortion (spontaneous or induced; P=.12).
    • 12.8% vs 12.9% for preterm delivery (P=.96).
    • 8.9% vs 9.0% for congenital malformation (P=.89).
  • In patients who received surgery and RAI, an interval of 0-5 months between RAI and conception was associated with an increased odds of congenital malformation (OR, 1.74; P=.04) and abortion (OR, 4.08; P<.001 compared with an interval of months. style="list-style-type:circle;">
  • An interval of 6-11 months was not associated with risk for adverse pregnancy outcomes (OR, 1.16 [P=.14] for abortion; OR, 1.10 [P=.57] for preterm delivery; OR, 0.95 [P=.80] for congenital malformation).

Study design

  • 111,459 women of childbearing age with thyroid cancer who underwent thyroidectomy with or without RAI were included.
  • Funding: None disclosed.

Limitations

  • Retrospective analysis of large database.