ESPE Abstracts

Background: Graves’ disease (GD) is the most common cause of hyperthyroidism in fertile woman and can cause fetal and neonatal hyper or hypothyroidism. It is associated with transplacental transfer of maternal thyrotropin receptor antibodies (TRAb).

Objective and hypotheses: The main objective of this study was to characterize the neonates born to women with GD followed in a pediatric endocrinology reference unit.

Method: A retrospective chart review was done of neonates born to mothers with GD in the last 14 years. The parameters analysed were: maternal thyroid function and treatment during or before pregnancy, sex, gestational age, birth weight, newborn thyroid function and treatment.

Results: Twenty RN neonates (55% female) were included, of 18 mothers with GD. Median gestational age was 37.7 (±1.2) weeks, with three pre-terms (35 and 36 weeks), 35% of first gestations. Mean birth weight was 2778.5 g (±437.6), with one born small for gestational age. One pregnancy was complicated by pre-eclampsia and in two fetus ultrasound changes were found (fetal goiter, oligohydramnios and intrauterine growth restriction). GD was diagnosed 3.1 years (±2.4, n=16) before the childbirth. Four mothers were submitted to ablative treatment with radioiodine. TRAb were elevated in the third trimester (>1 IU/l; maximum: 40 IU/l) in five pregnancies, four of which were treated with antithyroid drugs (ATD). Three newborns presented with hyper and four with hypothyroidism, whose mothers presented with elevated TRAb late in pregnancy. Half of the hypothyroid newborns were treated with thyroxine. There was only one baby with overt hyperthyroidism that was treated with methimazole for 4 months.

Conclusion: There were an elevated number of newborns of GD mothers with abnormal thyroid function tests, mostly in uncontrolled mothers during pregnancy (all with elevated TRAb). We recommend an optimal follow up of these mothers and the establishment an adequate management protocol for the neonates.