Follow-Up of Thyroid Function in Children With Neonatal Hyperthyroidism.

Area of Science:

• Endocrinology
• Neonatal care
• Thyroid disorders

Background:

• Neonatal hyperthyroidism often arises in infants of mothers with Graves' disease (GD).
• Maternal Graves' disease can lead to various neonatal thyroid dysfunctions, including hyperthyroidism and hypothyroidism.
• Maternally transferred thyrotropin receptor antibodies (TRAb), antenatal antithyroid drug (ATD) use, and prior maternal GD treatments influence fetal/neonatal thyroid function.

Purpose of the Study:

• To evaluate the spectrum of thyroid dysfunction in neonates presenting with hyperthyroidism.
• To investigate the occurrence of central hypothyroidism (CeH) in infants born to mothers with GD.
• To identify potential indicators for delayed CeH diagnosis in this population.

Main Methods:

• Retrospective analysis of medical records for 14 infants diagnosed with neonatal hyperthyroidism.
• Categorization of thyroid dysfunction based on thyroid hormone levels (fT4, fT3) and TSH.
• Assessment of thyrotropin receptor antibody (TRAb) levels in neonates and mothers.

Main Results:

• Transient hyperthyroidism was the predominant condition, observed in all 14 infants.
• Overt hyperthyroidism with high TRAb levels was seen in 43% of neonates.
• Central hypothyroidism (CeH) or primary hypothyroidism necessitated levothyroxine (L-T4) supplementation in 28.5% of cases.

Conclusions:

• Prolonged monitoring of thyroid function is essential for infants born to mothers with GD.
• Transient neonatal hyperthyroidism can mask the diagnosis of CeH.
• Sustained suppressed TSH levels post-TRAb normalization may signal impending CeH.