FETAL GOITRE IN MATERNAL GRAVES' DISEASE

Fetal goitre is found in about 1 in 5,000 births, usually in association with maternal Graves' disease, due to transplacental passage of high levels of thyroid stimulating antibodies or of anti-thyroid drugs. A goitre can cause complications attributable to its size and to the associated thyroid dysfunction. Fetal ultrasound examination allows easy recognition of the goitre but is not reliable in distinguishing between fetal hypo- and hyperthyroidism. Assessment of the maternal condition and, in some cases, cordocentesis provide adequate diagnosis of the fetal thyroid function. First-line treatment consists of adjusting the dose of maternal anti-thyroid drugs. Delivery is aimed at term. In cases with large goitres, caesarean-section is indicated.