American Thyroid Association Quick-Reference GUIDELINES Apps
Issue link: https://eguideline.guidelinecentral.com/i/789888
9 Î The recommended treatment of maternal hypothyroidism is administration of oral LT4. Other thyroid preparations such as T3 or desiccated thyroid should NOT be used in pregnancy. (S-L) Î In parallel to the treatment of hypothyroidism in a general population, it is reasonable to target a TSH in the lower half of the trimester specific reference range. When this is not available, it is reasonable to target maternal TSH concentrations <2.5 mU/L. (W-M) Î Women with overt and subclinical hypothyroidism (treated or untreated), or those at risk for hypothyroidism (e.g. patients who are euthyroid but TPO or TGAb positive, posthemithyroidectomy, or treated with radioactive iodine) should be monitored with a serum TSH measurement approximately every 4 weeks until mid-gestation, and at least once near 30 weeks gestation. (S-H) Î Treated hypothyroid women of reproductive age should be counseled regarding the likelihood of increased demand for LT4 during pregnancy. Such women should also be counseled to contact their caregiver immediately upon a confirmed or suspected pregnancy. (S-H) Î In hypothyroid women treated with LT4 who are planning pregnancy, serum TSH should be evaluated preconception, and LT4 dose adjusted to achieve a TSH value between the lower reference limit and 2.5 mU/L. (S-M) Î Following delivery, LT4 should be reduced to the patient's preconception dose. Additional thyroid function testing should be performed at approximately 6 weeks postpartum. (S-M) Î Some women in whom LT4 is initiated during pregnancy may not require LT4 postpartum. Such women are candidates for discontinuing LT4, especially when the LT4 dose is ≤50 mcg daily. The decision to discontinue LT4, if desired, should be made by the patient and their caregiver. If LT4 is discontinued, serum TSH should be evaluated in ~6 weeks. (W-M) Î In the care of women with adequately treated hypothyroidism, no other maternal or fetal testing (such as serial fetal ultrasounds, antenatal testing, and/or umbilical blood sampling) is recommended beyond measurement of maternal thyroid function unless needed due to other circumstances of pregnancy. An exception to this is women with Graves' disease effectively treated with 131 I ablation or surgical resection, who require thyrotropin receptor antibodies (TRAb) monitoring. (S-M)