Question

In pregnancy which of the following level is altered mostly:

• A. Total T₃
• B. Free T₃
• C. Free T₄
• D. TSH

Answer 1

The Correct Option is A

During pregnancy, numerous physiological changes occur in the body, one of which involves alterations in thyroid hormone levels. This is due to increased production of thyroid-binding globulin (TBG) stimulated by elevated estrogen levels. As a result:

• Total T₃ (Triiodothyronine): This is the primary thyroid hormone that's predominantly altered. The increased TBG binds more T₃, leading to a rise in total T₃ levels.
• Free T₃: The free portion remains relatively constant because the body adjusts to maintain euthyroid status despite the increase in binding protein.
• Free T₄: Similar to free T₃, free T₄ also stays relatively stable.
• TSH (Thyroid Stimulating Hormone): It may slightly fluctuate but typically stays within normal limits due to the body's compensatory mechanisms.

In summary, the most significant change is seen in the Total T₃ level, which increases due to heightened TBG levels.