Abstract

Neonatal hyperthyroidism is a disease that can cause mortality and sequelae. To date, there is no clinical series of cases that allows us to know the local reality of this condition. Objective: to characterize the children of mothers with Graves’ disease (GD) from a clinical and biochemical point of view. Subjects and Method: A prospective follow-up of all newborns (NB) of mothers with history of GD was performed in two public hospitals in Santiago, during 5 years. Clinical and laboratory variables of mother-child pairs and thyroid-stimulating hormone receptor antibodies (TRAbs) levels were analyzed looking for associations between these variables and the development of neonatal hyperthyroidism. Results: Seventy-six mother-child pairs were included (0.2% of all deliveries). Five neonates (6.6%) presented biochemical hyperthyroidism, and 3 of them developed clinical disease and required treatment. All 5 NBs who developed hyperthyroidism had mothers with positive or indeterminate TRAbs. No child of TRAbs-negative mothers developed the disease. TRAbs could be determined in only 65% of the mothers and 72% of the NBs. There was a significant correlation between maternal TRAbs titers (p < 0.03), neonatal TRAbs titers (p < 0.008), and neonatal TSH between days 2-6 (p < 0.006), with the subsequent development of hyperthyroidism. All cases of neonatal hyperthyroidism were transient. There was no mortality in our series. Conclusions: This is the first national case series of children of mothers with GD. Maternal and neonatal TRAbs and TSH between days 2-6 of life were predictors of neonatal hyperthyroidism.