What is a primary side effect of Methimazole (Tapazole) related to pregnancy?

Methimazole (Tapazole) is an antithyroid medication used to manage hyperthyroidism by inhibiting the synthesis of thyroid hormones. During pregnancy, it is particularly important to consider the safety of medications, especially in the first trimester when fetal development is most sensitive to the effects of drugs.

The primary concern with Methimazole during the first trimester is its association with certain congenital anomalies, including craniofacial defects, limb abnormalities, and other malformations. Due to these risks, it is recommended that Methimazole be avoided in the first trimester of pregnancy, emphasizing the importance of providing safer alternatives, such as propylthiouracil (PTU), until after the first trimester.

This understanding highlights the critical role of monitoring and managing hyperthyroidism in pregnant individuals, ensuring both maternal health and fetal safety.