Struma ovarii is a rare type of ovarian teratoma primarily composed of over 50% thyroid tissue. Its occurrence is reported in 2–5% of all ovarian teratomas, with approximately 0.5% to 10% showing malignant transformation. Managing it during pregnancy poses significant challenges as pregnancy can promote the growth of malignant struma ovarii due to elevated levels of ovarian and pregnancy-related hormones, including estrogen, progesterone, and human chorionic gonadotrophin (hCG). Most ovarian tumors, including struma ovarii, are detected during routine ultrasonography in the first and second trimesters, often as acute emergencies. Diagnosis during pregnancy is rare, with some cases incidentally discovered during cesarean section when inspecting the adnexa for ovarian cysts. This review explores the diagnostic, management, and therapeutic approaches to struma ovarii during pregnancy.
