Intrauterine diagnosis and management of congenital goitrous hypothyroidism.

The intrauterine recognition and treatment of congenital goitrous hypothyroidism may not only reduce the obstetric complications associated with large goiters, but possibly improve the prognosis for normal growth and mental development of affected fetuses. We present a case of fetal goiter diagnosed at 29 weeks of gestation following routine ultrasound examination. Fetal blood sampling performed at this time confirmed the presence of fetal hypothyroidism. Treatment was performed using a series of intra-amniotic injections between 31 and 36 weeks, initially with tri-iodothyronine (T3) and subsequently with thyroxine. During this period, shrinkage of the fetal goiter, increasing neck flexion and resolution of the polyhydramnios was observed. Following birth, neonatal serum thyroid-stimulating hormone levels were within the normal range but thyroxine was reduced. The baby was started on daily oral thyroxine and, on examination 7 weeks following birth, he appeared clinically and chemically euthyroid. In the absence of maternal thyroid disease, fetal goiter is extremely rare, with only seven cases previously reported in the English literature to have used intra-amniotic thyroxine injections as a form of treatment. This report reviews the current literature regarding the diagnosis and intrauterine management of fetal goiter and considers the possibility of T3 therapy in future cases of congenital hypothyroidism.