Which laboratory evaluation is commonly included in the workup for recurrent pregnancy loss?

• A. Sperm morphology
• B. Autoimmune panel
• C. Pelvic imaging
• D. Thyroid function

Answer: (D)

Thyroid health directly influences early pregnancy viability. The fetus relies on maternal thyroid hormone during the first trimester because its own thyroid isn’t fully functional yet, so thyroid problems can impair implantation and placental development and raise the risk of miscarriage. That makes thyroid function tests a standard part of the recurrent pregnancy loss workup.

Practically, clinicians commonly check TSH and free T4 to assess overall thyroid status, looking for overt or subclinical hypothyroidism or hyperthyroidism. Subclinical hypothyroidism—elevated TSH with normal free T4—has been associated with higher miscarriage risk in some settings, so identifying it can change management. Many providers also check thyroid antibodies, such as anti-thyroid peroxidase (anti-TPO), because autoimmune thyroid disease can coexist with thyroid dysfunction and has been linked to pregnancy losses even when thyroid hormone levels appear normal.

In contrast, the other options you might see in a list—sperm morphology, pelvic imaging, or broad autoimmune panels—cover different aspects of fertility workups and are not as universally standardized as a thyroid screen in the context of recurrent pregnancy loss.