There are at least two notable recommendations that did not change but warrant mention because of their importance. Neonates of women with definitively treated Graves’ disease (status post thyroidectomy or treatment with I131 before pregnancy) have a higher risk of neonatal Graves disease compared with women with Graves disease currently on thioamide treatment during pregnancy. This is because the definitively treated women still have thyroid-stimulating antibodies that cross the placenta and could affect the fetus but they have no concurrent thioamide treatment, a drug that also crosses the placenta. Furthermore, we tend to forget these women had Graves disease because they are on thyroid replacement and, in our minds, they are labeled as having hypothyroidism.
The second affirmation is that routine measurements of thyroid function in women with hyperemesis gravidarum are still not recommended because it is well known that transient laboratory findings consistent with hyperthyroidism occur in the first trimester and are more common in women who have hyperemesis and that this transient gestational hyperthyroidism resolves and is not impacted by treatment.
Finally, the 2015 practice bulletin ends with a bit of a provocative “negative” performance measure: the percent of women without risk factors for thyroid disease during pregnancy who are nevertheless screened for thyroid disease. So, heed the above recommendation: Do not routinely screen women in pregnancy for thyroid disease.
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