Can low TSH levels be normal during pregnancy?

Yes, low TSH levels can be normal during the first trimester of pregnancy due to increased production of human chorionic gonadotropin (hCG), which stimulates the thyroid to produce more T4. This temporarily suppresses TSH levels, mimicking hyperthyroidism. However, very low TSH levels, especially in the later stages of pregnancy, may indicate hyperthyroidism and require monitoring. Maintaining appropriate thyroid function is crucial during pregnancy for both maternal health and fetal development. Your healthcare provider will monitor TSH, T3, and T4 levels closely during pregnancy.