Central Hypothyroidism in Infants Who Were Born to Mothers With Thyrotoxicosis Before 32 Weeks' Gestation: 3 Cases

We describe 3 infants who were born to mothers with Graves' disease and developed central hypothyroidism that persisted for >6 months after birth. Two were preterm infants, and the other was a term infant who was born to a euthyroid mother who had been treated with an antithyroid drug since week 31 of gestation. These cases suggest that passage of thyroid hormones can occur from a thyrotoxic mother to the fetus and that the gestational period earlier than 32 weeks may be the critical time for development of central hypothyroidism.