Elsevier

Annales d'Endocrinologie

Volume 74, Issue 1, February 2013, Pages 62-64
Annales d'Endocrinologie

Clinical case
Infant's bilobar thyroid agenesis and mother's I-131 accidental administrationAgénésie thyroïdienne bilobaire chez le nouveau-né après administration accidentelle d’iode-131 pendant la grossesse

https://doi.org/10.1016/j.ando.2012.10.004Get rights and content

Abstract

Bilobar thyroid agenesis is one of rare diseases. Genetic and environmental factors may associate with bilobar thyroid agenesis. But the mechanism is still not completely understood. It had been showed that I-131 administration during pregnancy may induce thyroid dysfunction in newborn. Here we reported a case of female hospital staff who received I-131 accidently during (10–12th gestational weeks) and after her pregnancy. The absorbed dose to fetus was higher than 30 mGy. At birth, the infant was found to have no thyroid. It was speculated that the fetal thyroid agenesis may be related with mother’ I-131 administration during pregnancy. In addition, this case report also indicated that the radiation dose should be minimized to any developing embryo.

Résumé

L’agénésie thyroïdienne bilobaire est une maladie rare associée à des facteurs génétiques et environnementaux. Le mécanisme n’est pas totalement élucidé. Il est démontré que l’administration d’iode-131 chez la femme enceinte peut induire une dysfonction thyroïdienne chez le nouveau-né. Nous présentons le cas d’une soignante ayant reçu accidentellement de l’iode-131 pendant la grossesse (10–12 semaines d’aménorrhée) et après l’accouchement. La dose absorbée était de plus de 30 mGy. À sa naissance, l’enfant n’avait pas de glande thyroïde. L’hypothèse d’une agénésie thyroïdienne fœtale en rapport avec l’administration d’iode-131 pendant la grossesse est discutée. En plus, ce cas montre l’importance d’une réduction de dose de radiation pendant le développement de l’embryon.

Introduction

I-131 has been widely used in nuclear medicine for treatment of Graves’ disease or thyroid cancer. Few reports regarding fetal uptake of radionuclide after radioiodine treatment of pregnant women have been published [1], [2]. There still remain many questions about the clinical outcome of the fetus in this accidental clinical situation. In this paper, we present the case of a woman who received I-131 during and after pregnancy and report the fetal outcome.

Section snippets

Case presentation and discussion

In May 2007, the dosimeter of a female staff member in the department of nuclear medicine reached 9.4 mSv. A urine sample was collected and the gamma spectrum analysis showed that the isotope was I-131. According to ICRP publications and other references [3], [4], we estimated that the total radioactivity of administered I-131 was greater than 10 mCi (9–22 mCi). Further information showed that the woman had an 8-month-old infant who was born at full term, but had no thyroid; both lobes of the

Conclusions

Earlier data also suggested that there is a threshold for radiation effects. But data from Chernobyl fallout did demonstrate an increased risk of thyroid cancer [15]. In this case report, we speculate that I-131 administration during pregnancy may be associated with infant thyroid agenesis. However, bilobar thyroid agenesis is an exceptionally rare phenomenon. Further investigations are needed to determine whether the bilobar thyroid agenesis is inevitable or incidental for this case. In

Disclosure of interest

The authors declare that they have no conflicts of interest concerning this article.

References (15)

  • C. Sioka et al.

    Effects of I-131 therapy on gonads and pregnancy outcome in patients with thyroid cancer

    Fertil Steril

    (2011)
  • G.E.B. Berg et al.

    Radioiodine treatment of hyperthyroidism in a pregnant woman

    J Nucl Med

    (1998)
  • P.M.S. Evans et al.

    Radioiodine treatment in unsuspected pregnancy

    Clin Endocrinol

    (1998)
  • E.T. Lessard

    Interpretation of bioassay measurements. NUREG/CR 4884

    (1988)
  • ICRP 68

    Dose coefficients for intake of radionuclides by workers

    Ann ICRP

    (1994)
  • G. Berg et al.

    Consequences of inadvertent radioiodine treatment of Graves’ disease and thyroid cancer in undiagnosed pregnancy. Can we rely on routine pregnancy testing?

    Acta Oncologica

    (2008)
  • ICRP 88

    Doses to the embryo and fetus from intakes of radionuclides by the mother

    Ann ICRP

    (2001)
There are more references available in the full text version of this article.

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  • Thyroid hormones, iodine and iodides and antithyroid drugs

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    Citation Excerpt :

    Compounding factors in this case were use of steroids to treat asthma and deliberate vitamin D deficiency. Fetotoxicity A rare disease of bilobar thyroid agenesis occurred in an infant whose mother was accidentally exposed to 131I during early pregnancy at an estimated dosage 30 mGy (10–12 weeks gestation) [27A]. This dose was lower than previously reported (SEDA-32, 765).

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