Speciality certificate examination Endocrinology sample question
A 27 year old female diagnosed with Graves’ disease taking propylthiouracil has presented to endocrinology OPD. She is in her 5th month of gestation. Her latest TFTs reveal euthyroidsm. She is curious to know about the risk of her child developing the disease. What is the best predictor of neonatal hyperthyroidism?
- TSH receptor antibody in mother in last trimester.
- TSH receptor antibody in neonatal blood.
- T3 T4 levels in mother in last trimester.
- TSH receptor antibody in mother in first trimester.
- T3 T4 levels in neonatal blood.
CORRECT ANSWER A
- If a pregnant woman is euthyroid but has previously been treated for Graves’ disease by radioiodine or thyroid surgery, the risk for neonatal hyperthyroidism is not negligible, and depends primarily on the level of TSH-receptor antibodies in her serum.
- A pregnant woman who takes antithyroid drugs for Graves’ disease to keep thyroid function normal (therapy has been started before or during pregnancy): TSH-receptor antibodies should be measured in the last trimester. If antibodies are absent, or the levels low, neonatal hyperthyroidism is unlikely. If antibody levels are high, evaluation for neonatal hyperthyroidism is needed (clinical evaluation and thyroid function tests on cord blood and again after 4–7 days to detect early and delayed hyperthyroidism.
- The best predictor of neonatal hyperthyroidism is a high level of TSH-receptor antibodies in the pregnant woman measured late in pregnancy.