New recommendation for hypothyroidism during pregnancy cutoff level for TSH

Dear Dr Kajal Verma, The latest ATA guidelines regarding Hypothyroidism in Pregnancy are rather Very Confusing. Earlier guidelines were very clear cut, now that there is lot of nonsense going on with the vague guidelines, I remember the JNC 8 guidelines regarding Hypertension. As per the latest 2020 ATA guidelines, the cut off point is raised to 4 mU/L from 2.5 mU/L (against 2011 guidelines) According to 2011 guidelines TSH levels are First Trimester 0.1 to 2.5 Second Trimester 0.2 to 3 Third Trimester 0.3 to 3. According to 2020 ATA guidelines 1) If the TSH in Pregnancy is more than 2.5, order Anti TPO Antibodies. In the first Trimester the lower reference range of TSH can be reduced by approximately 0.4 mU/L while the upper reference range is reduced by approximately 0.5 mU/L. 2) For the typical patient in early pregnancy this corresponds to TSH upper reference limit of 4.0 mU/L 3) All breast feeding women should ingest approximately 250 mcg of Dietary Iodine daily 4) Euthyroid prenant women who are TPO Ab or Tg Ab should have measurement of Serum TSH concentration performed at time of pregnancy confirmation and every 4 weeks through mid pregnancy. 5) Insufficient evidence exists to recommend for or against treating Euthyroid Pregnant women who are Thyroid Auto Antibody Positive with Thyroxine to prevent pre term delivery. 6) Treatment of Overt Hypothyroidism is recommended during pregnancy. 7) The following recommendations are for SCH in Pregnancy A) Thyroxine Therapy is recommended for TPO Antibodies Positive women with a TSH more than the Pregnancy specific reference range. B) Thyroxine Therapy may be considered for TPO Ab Positive women with TSH concentrations more than 2.5 mU/L and less than the upper limit of pregnancy specific reference range. C) Thyroxine Therapy is not recommended for TPO Ab women with a normal TSH, (TSH within the Pregnancy specific reference range or less than 4 mU/L) 8) When TSH less than the reference detected in the first Trimester a Medical history, Physical Examination, measurement of Maternal serum FT4 or TT4 concentrations should be performed. 9) Thyroid nodules, FNAC is generally recommended for newly detected nodules in pregnant women with a non suppressed TSH. Determination of which nodule requires FNAC should be based upon the nodules sonographic pattern. 10) Pregnant women with cytologically benign nodules do not require special surveillance during pregnancy. 11) PTC detected in early pregnancy should be monitored sonographycally, if it grows substantially before 24th to 26th weeks Gestation, OR if malignant cervical lymph nodes are present, Surgery should be considered during pregnancy. How ever if the disease remains stable by mid Gestation or is diagnosed in the second half of pregnancy Surgery may be deferred until after delivery. 12) A delay in treatment Medullary Carcinoma or Anaplastic Cancer diagnosed during pregnancy is likely to adversely affect outcomes. Therefore Surgery should be strongly considered. 13) The use of 131I is contraindicated during lactation. 123I can be used if breastmilk is pumped and discarded 3 to 4 days before brest feeding is resumed. Similarly Tc 99 m pertechnetate administration requires breast milk to be pumped and discarded during the day of testing. 14) Low to Moderate doses of both PTU and MMI/CM are safe in breast feeding infants. How ever maximal daily doses of 20 mg MMI or 450 mg PTU are advised. Regards and thanks, Dr Sepuri Krishna Mohan.
- TSH 0.5 miu/L lower then prepregnancy level is cutoff level
A new recommendation indicate that levothyroxine treatment can be considered for a TSH above the reference range ofTPOab Negative women While TPO AB positive women treatment can be considered fromTSH above2.5mu/ l High risk of missed and preterm del inTPOab positive