Fetal goiter treated antenatally with intra-amniotic thyroxine: A case report

Fetal goiter may compromise the airway and complicate delivery. Prenatal management requires assessment of fetal thyroid function and the mass effect of the enlarged gland. A fetal neck mass was detected at 18 + 5 weeks of gestation in a 32-year-old woman with a history of Hashimoto thyroiditis. Ultrasonography confirmed a bilobed goiter with neck hyperextension and apparent tracheal compression, and fetal hypothyroidism was confirmed by cordocentesis. Eleven intra-amniotic levothyroxine injections were administered between 24 + 4 and 35 + 6 weeks of gestation, initially at a dose of 400 μg and subsequently increased to 600 μg. Serial ultrasonography and hormonal monitoring showed progressive reduction in thyroid volume, resolution of the apparent tracheal compression, and restoration of normal fetal neck flexion. Following premature rupture of membranes, a girl was delivered by cesarean section at 36 + 3 weeks without a clinically apparent goiter. She received neonatal levothyroxine and, at 14 months, showed adequate growth and normal neurological and psychomotor development. Prenatal imaging and assessment of fetal thyroid function can identify thyroid disorders that may be amenable to treatment in utero. In the absence of a standardized intra-amniotic levothyroxine regimen, treatment should be individualized and coordinated by a multidisciplinary team.