Hormone replacement therapy in TPOAb-negative pregnant women with subclinical hypothyroidism

Is there ever a need for hormone replacement therapy with levothyroxine in thyroid peroxidase antibody (TPOAb)-negative pregnant women with subclinical hypothyroidism?

Leonard Wartofsky, MD: If there is subclinical hypothyroidism—again, normal thyroxine (T₄) and triiodothyronine (T₃) but a slightly elevated thyroid-stimulating hormone (TSH) [see Diagnosis of subclinical hypothyroidism in pregnancy]—even in a TPOAb-negative patient, I would start thyroxine therapy for the benefit of the pregnancy.

With subclinical hypothyroidism there is a greater risk of miscarriage and for outcome of pregnancy that justifies the very small risk of thyroxine therapy, if any.