Evaluation and management of infants at risk for neonatal Graves disease

DOL: day of life; fT4: free thyroxine; MMI: methimazole; T3: triiodothyronine; TSH: thyroid-stimulating hormone; TSH-R: thyroid-stimulating hormone receptor; TSHR-Ab: thyroid-stimulating hormone receptor antibodies.

* Infants may come to attention after birth if the history of maternal Graves disease is not recognized until after birth, and/or if the infant presents with symptoms leading to a clinical diagnosis of neonatal Graves disease. For these infants, thyroid function tests are performed as soon as the possibility of neonatal Graves disease is recognized and repeated during the first 2 weeks of life, as shown. Results of maternal TSHR-Ab tests, if available, may be helpful to estimate the infant's risk of developing neonatal Graves disease.

¶ Follow-up is recommended because some TSHR-Ab tests may have false-negative results.

Δ Thyroid function tests should be interpreted in the context of the infant's gestational and chronologic age because the normal values for these tests are higher during the first few weeks of life compared with values in older infants (refer to UpToDate topic text for details).

◊ Starting treatment with MMI requires clinical judgment. For infants with clearly elevated serum fT4 and total T3 concentrations and thyrotoxic clinical manifestations, we suggest starting MMI. For infants with mild fT4 and total T3 elevations and minimal or no thyrotoxic features, we suggest serial monitoring of thyroid function tests and symptoms to inform management.

§ In most of these infants, the hypothyroidism is transient and is due to maternal antithyroid drug treatments, although some cases are caused by maternal TSH-R blocking antibodies. The infant may become euthyroid or hyperthyroid anytime during the first few weeks of life. As neonatal Graves disease resolves, some infants may develop central hypothyroidism (low fT4 and low TSH). Central hypothyroidism also may be transient but should be treated with levothyroxine until the hypothyroidism resolves.