What is the most appropriate treatment for a 34-year-old woman with hyperthyroidism planning a pregnancy?

For a woman with hyperthyroidism who is planning a pregnancy, the most appropriate treatment option is antithyroid medications. These medications effectively manage hyperthyroidism while being safer to use during the preconception period compared to other options.

Antithyroid medications, such as propylthiouracil (PTU) or methimazole, can control thyroid hormone levels. It is essential to stabilize the patient's thyroid function before conception to reduce the risks of complications during pregnancy, which can include issues like maternal heart problems or fetal developmental delays.

In contrast, iodine therapy and radioactive iodine treatment are not recommended for women who are planning to conceive. These treatments can impact future pregnancies and fetal development negatively due to the high levels of radiation involved. Thyroidectomy, while a potential long-term solution for hyperthyroidism, is generally not preferred in a patient wishing to conceive soon, as it requires more extensive recovery and may pose surgical risks.

Thus, the most appropriate approach prior to pregnancy is to use antithyroid medications to manage the condition effectively.