Pregnancy induces the presence of a thyroid-stimulating antibody in a thyrotropin-binding inhibitory immunoglobulin positive, hypothyroid woman with transient thyrotoxicosis in offspring.
A 27-year-old woman had a goiter and transient hyperthyroidism when she was 18 years old. Symptoms subsided after treatment with medication (without use of radioactive iodine) for one month. She delivered a child without complications at 23 years of age. Hypothyroidism developed when she was 25 years old. Under the impression of autoimmune thyroiditis with hypothyroidism, she was treated with levothyroxine 150 micrograms/day. She became pregnant again one year later. Her thyrotropin-binding inhibitory immunoglobulin (TBII) was very high before and during pregnancy, and after delivery. Thyroid-stimulating antibody (TSAb) was not detectable during the 2nd trimester, but elevated in association with a decrease in dosage of levothyroxine during the 3rd trimester. She delivered a male baby at full-term. The newborn's TBII was high at 4 days old and it gradually developed into hyperthyroidism with symptoms of irritability, poor weight gain, tachycardia and jaundice. Hyperthyroidism subsided after temporary treatment with methimazole and propranolol. The medication was discontinued at the age of 82 days. Follow-up thyroid function was normal at the age of three and a half months. In the mother, TSAb gradually decreased, although TBII was still very high. The dosage of levothyroxine was again increased. This study demonstrates that pregnancy may alter the ratio of TBII and TSAb, and modify the functional state of the thyroid of the mother. Therefore, in patients with autoimmune thyroiditis during pregnancy, serial follow-up of thyroid function and TBII (and TSAb, if possible) may help the doctor to properly adjust the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
Chang
T C
TC
Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, R.O.C.
Lee
J S
JS
D000328:Adult; D001323:Autoantibodies / Q000032:analysis*; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000276:immunology*; D018828:Immunoglobulins, Thyroid-Stimulating; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D011248:Pregnancy Complications / Q000276:immunology*; D013961:Thyroid Gland / Q000276:immunology*; D013967:Thyroiditis, Autoimmune / Q000276:immunology; D013971:Thyrotoxicosis / Q000209:etiology*
D001323:Autoantibodies; D018828:Immunoglobulins, Thyroid-Stimulating