Background Hyperthyroidism is one of the most common endocrine disorders in pregnant
women, and it can severely complicate the course and outcome of pregnancy. Methimazole
(MMI) and propylthiouracil (PTU) are the standard anti-thyroid drugs used in the treatment of
hyperthyroidism in pregnancy. Traditionally, MMI has been considered to have clearer
evidence of teratogenicity than PTU. Recent studies suggest that PTU can be hepatotoxic,
leading to a United States Food and Drug Administration “black box alert.” We wished to …