Which lab hallmark is NOT associated with postpartum thyroiditis?

Postpartum thyroiditis is a condition that typically occurs within the first year after delivery and is characterized by inflammation of the thyroid gland, leading to alterations in thyroid hormone levels. The hallmark features of postpartum thyroiditis include the presence of antithyroid antibodies, often elevated levels of free T4 during the hyperthyroid phase, and a transient decrease in TSH levels due to increased thyroid hormone output.

The presence of antithyroid antibodies is significant because it reflects the autoimmune component of this condition. In many cases, women with postpartum thyroiditis will test positive for these antibodies, even if they do not have overt thyroid disease prior to pregnancy.

During the initial hyperthyroid phase, increased free T4 levels can be seen due to the release of stored thyroid hormones from the inflamed thyroid gland. This increase in thyroid hormones leads to a compensatory decrease in TSH levels, as thyroid regulation is governed by a feedback mechanism involving the pituitary gland.

The correct option indicates that elevated TSH levels are not characteristic of postpartum thyroiditis. In fact, during the hyperthyroid phase, TSH is typically suppressed due to the high levels of circulating thyroid hormones. Eventually, as the disease progresses towards hypothyroidism, if it occurs, TSH