Detection and evaluation of fetal goitre by ultrasound.

Antenatal diagnosis of fetal goitre has been reported rarely. Once detected, however, it is important to evaluate fetal thyroid function so early treatment can be initiated if necessary. In reporting three new cases, the authors analyse the various methods of evaluation. The normal sequence of appearance of the various epiphyseal ossification centres is an indirect illustration of thyroid function and can be followed by ultrasound. Direct evaluation of hormone levels through cord blood sampling under sonographic guidance is a complementary method in doubtful cases. The mechanisms predisposing to the development of fetal goitres and the possible implications of these findings are also discussed.