ABSTRACT
Thyroid nodules are common with a large number occurring in women of childbearing age. Thyroid nodule growth is typically gradual and most nodules detected during pregnancy were likely present before conception. Pregnant females often have greater contact with medical providers leading to initial detection of thyroid nodules during pregnancy. Roughly 8–16% of thyroid nodules represent cancer; however, thyroid malignancy is now the fifth most common cancer in women in the general population. In the setting of pregnancy, thyroid malignancy is the second most common cancer detected. The evaluation of thyroid nodules in pregnant women is similar to the general population with few exceptions. Initial diagnostic evaluation includes measurement of serum thyroid-stimulating hormone (TSH) and ultrasonography of the thyroid gland and cervical lymph nodes. In a patient with a normal or elevated serum TSH and a nodule on exam, fine needle aspiration (FNA) biopsy is determined based upon size and sonographic appearance defined by the American Thyroid Association guidelines. Nodules with benign cytopathology and nodules not meeting criteria for biopsy may be followed clinically and with repeat ultrasound imaging in 12–24 months. For women with a suppressed serum TSH level that persists beyond 16 weeks of gestation, further evaluation of a clinically relevant thyroid nodule may be deferred until after delivery. After pregnancy and if serum TSH remains suppressed, a radionuclide scan can be safely performed.
