Choanal atresia associated with prenatal methimazole exposure: three new patients

Am J Med Genet A. 2004 Aug 15;129A(1):83-6. doi: 10.1002/ajmg.a.20668.


We report three patients with bilateral choanal atresia in children prenatally exposed to methimazole (MMI) in order to define a MMI embryopathy clinical pattern. The combination of choanal atresia and other specific malformations strongly resembles previously reported patients exposed to MMI in utero. At present, propylthiouracil is considered the best treatment in pregnancies. However in Argentina and some other countries MMI is the only antithyroid drug, possibly posing a significant risk to the unborn fetus.

Publication types

  • Review

MeSH terms

  • Antithyroid Agents / adverse effects*
  • Antithyroid Agents / therapeutic use
  • Choanal Atresia / chemically induced*
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Methimazole / adverse effects*
  • Methimazole / therapeutic use
  • Pregnancy
  • Pregnancy Complications / drug therapy
  • Prenatal Exposure Delayed Effects*
  • Thyrotoxicosis / drug therapy


  • Antithyroid Agents
  • Methimazole