Pregnancy has a profound impact on thyroid gland function, and thyroid disease is common in pregnancy, with an approximated 300,000 pregnancies affected by thyroid disease in the United States yearly.2 Yet, there is considerable argument over the ideal treatment of hyperthyroidism during pregnancy. Thyroxine should be started as quickly hypothyroidism diagnosis and treatment guidelines as CH is confirmed on TFTs. Treatment is suggested if serum FT4 concentration is below age standards, and need to be considered where FT4 is typical however TSH > 20 mU/l3. The treatment goals are to keep FT4 in the upper third of the age-specific reference variety (or just above this), and TSH within the regular variety.
Hynes KL, Otahal P, Hay I, Citizen JR. Mild iodine shortage throughout pregnancy is connected with decreased instructional outcomes in the offspring: 9-year follow-up of the gestational iodine mate. J Clin Endocrinol Metab 2013; 98: 1954-1962. Temporal patterns for thyroid cancer in Australia: an increasing occurrence of papillary thyroid cancer (1982-1997). Thyroid 2002; 12: 141-149.
Three thyroxine preparations are readily available in Australia. Two of these (Eutroxsig and Oroxine, Aspen Pharma) are interchangeable and identical. A third preparation, Eltroxin (Aspen Pharma), has actually recently been marketed. It has a different formula, a broader variety of tablet strengths and (unlike Eutroxsig/Oroxine) does not require refrigeration, so might be more convenient. Eltroxin product information states that it is not bioequivalent to Oroxine/Eutroxsig, however this is based upon a study utilizing single, big dosages of thyroxine in healthy volunteers, which might not anticipate medically pertinent distinctions throughout scientific use. 18 Because of this uncertainty, patients must not be switched between Eltroxin and Eutroxsig/Oroxine (or vice versa), other than where clearly intended by the prescribing doctor. Clients who do change brands must have their serum TSH examined 6 weeks later, and dosage changed if essential.
A normal/near typical FT4 after 1 week of treatment should prompt a dosage reduction of 20-30% in order to avoid subsequent over-treatment. Thyroid scintigraphy helps with the detection of structural problems and steps worldwide thyroid function as shown by radionuclide uptake and will generally provide specific diagnostic details that helps with counselling and treatment.
Early detection and prompt initiation of thyroxine replacement can prevent extreme cognitive problems and development failure. Hyperthyroidism is typically triggered by Graves’ disease, thyroiditis or hazardous nodular goitre. The cause ought to be developed before providing treatment. Radionuclide scanning is the imaging technique of option. Favorable TSH-receptor antibodies suggest Graves’ disease.
Serum thyroid function tests (venous or capillary), including TSH and free T4 (FT4). Regional experience supports a schedule of weekly TFTs for the 1st six weeks then monthly up until 1 year of age and 2-3 regular monthly in the Second year10. Ong GS, Hadlow NC, Brown SJ, et al. Does the thyroid-stimulating hormone measured simultaneously with very first trimester biochemical screening tests forecast unfavorable pregnancy outcomes occurring after 20 weeks gestation? J Clin Endocrinol Metab 2014; 99: E2668-E2672.
There are couple of medical trials of thyroxine in pregnancy. In one study, thyroxine treatment of TPOAb-positive, euthyroid pregnant women resulted in fewer miscarriages and preterm births. 47 More recently, thyroxine treatment of pregnant women with raised guidelines for the treatment of hypothyroidism TSH or lowered totally free T4 concentrations at a mean pregnancy of 12 weeks had no result on obstetric outcomes or on cognitive function in the offspring. 48 Other trials are in progress.