# Neonatal thyrotoxicosis secondary to maternal graves’ disease: a case report

## TL;DR

A newborn developed late-onset thyrotoxicosis due to maternal Graves’ disease, highlighting the need for maternal antibody screening and neonatal monitoring.

## Contribution

This case report emphasizes the importance of maternal TRAb screening and neonatal surveillance to prevent cardiac complications in infants of mothers with Graves’ disease.

## Key findings

- Late-onset neonatal thyrotoxicosis occurred despite maternal antithyroid medication and regular follow-up.
- The absence of maternal TRAb screening contributed to delayed diagnosis and cardiac complications like mitral regurgitation.
- Treatment with antithyroid medication and beta-blockers improved symptoms and biochemical parameters.

## Abstract

Neonatal thyrotoxicosis is a rare condition that often results from maternal antibody transfer, particularly in mothers who have had Graves’ disease. This disorder causes excessive thyroid hormone production in newborns. It can present with symptoms like tachycardia, poor weight gain, irritability, and, in severe cases, heart failure. Maintaining a high index of suspicion, making a prompt diagnosis, and intervening immediately are crucial. These steps help to mitigate the risk of long-term or serious complications.

We present a neonate with late-onset neonatal thyrotoxicosis. The baby was born to a mother with Graves’ disease, who was on antithyroid medication and regular endocrinology follow-up. The maternal thyroid receptor antibody (TRAb) test was unavailable on either the day of delivery or the re-admission day. The infant was initially stable and discharged on the third day of life without concerns. On day 14, he presented with tachypnea and tachycardia, requiring neonatal intensive care unit admission. Thyroid function tests and symptoms confirmed late onset of thyrotoxicosis (TSH: 0.002 µIU/mL, FT4: 49.6 pmol/L). After the treatment with antithyroid medication and beta-blockers, symptoms and biochemical parameters improved markedly, allowing discharge after the stabilization. This case uniquely illustrates the diagnostic challenges associated with late-onset neonatal thyrotoxicosis when maternal TRAb screening is omitted, potentially exacerbating cardiac complications like mitral regurgitation-a feature less emphasized in prior reports.

This case report highlights delayed-onset neonatal thyrotoxicosis complicated by mitral regurgitation, occurring in the context of absent maternal TRAb screening and early postnatal discharge. It demonstrates the masking effect of maternal antithyroid therapy and reveals deficiencies in anticipatory neonatal surveillance. This case expands the recognized spectrum of cardiac complications and emphasizes the importance of systematic maternal antibody screening. Further prospective studies are required to establish evidence-based surveillance protocols and cardiac risk stratification for neonates born to mothers with Graves’ disease.