Which medication is contraindicated for use during pregnancy due to potential teratogenic effects?

Methimazole is indeed contraindicated for use during pregnancy due to its potential teratogenic effects. This medication, which is a thionamide used to treat hyperthyroidism, has been associated with a variety of fetal anomalies, particularly when taken during the first trimester. Notably, it can lead to conditions such as aplasia cutis congenita, which is a congenital absence of skin, and other birth defects.

In contrast, propylthiouracil, while also a treatment for hyperthyroidism, is often considered safer during the first trimester of pregnancy because it has a lower risk of causing birth defects compared to methimazole. However, it is still essential to use it carefully under medical supervision, as it can have risks associated with its use later in pregnancy.

Lanreotide is a somatostatin analog primarily used for conditions like acromegaly and neuroendocrine tumors, but its teratogenic risk has not been established in the same way methimazole's has.

Follitropin, a form of follicle-stimulating hormone used for infertility treatments, does not have significant evidence of teratogenic effects.

Overall, the concern for teratogenicity is markedly higher with methim