RESUMO
This reports a case of congenital hypothyroidism associated with fetal polyhydramnios and severe neonatal hyponatremia. This patient is a premature 32- week infant who had poor oral feeding and severe hyponatremia that persisted till a diagnosis and treatment of hypothyroidism was established at the 37- week corrected age [5 weeks of age]. We here attempt to suggest another mechanism of polyhydramnios with hypothyroidism that is not linked to neck hyperextension. The relationship between poor feeding and swallowing in this patient and severe polyhydramnios was discussed. Literature review of the role of thyroid hormone in sodium homeostasis and urine output in relation to polyhydramnios was also discussed. This case report invites further research to understand the role of thyroid hormone in urine output and sodium homeostasis