Many patients that present to fertility centers are on thyroid supplements that are extracts from pig thyroid gland. Unfortunately, they have often embraced this treatment because it is presented as more “natural” then the synthetic thyroxine often prescribed by most healthcare providers. In reality, the human thyroid gland converts T4 (thyroxine) into T3 (the active form) very efficiently. The typical ratio of T4:T3 in humans is about 14:1. By contrast, pig thyroid extracts have a 4:1 ratio so that there is much more active T3 in the preparation. The problem with this high level of T3 is that the developing baby needs the T4 from a pregnant mom’s blood; not T3. High T3 levels during early pregnancy can impair healthy brain development. So I recommend the following:
–take a stable dose of thyroxine.
–If you still feel challenged; consider meeting with an endocrinologist to see if you might be a candidate for small supplemental dose of T3; two or three times per day.