Objective: Pre-natal ultrasonography presents an opportunity for in-utero therapy of a fetal goiter. Because of the morbidity associated with a large goiter and the risks of repeated intra-amniotic injections, controversy arose about the precise indications of this mode of treatment. We describe our observations in treating a 22-week-old fetus with a large goiter because of dyshormogenesis, monitored with serial 3D high frequency, high resolution ultrasonography and amniotic hormonal measurements. Fetal hypothyroidism was confirmed by cordocentesis and amniotic hormone levels. After assessment of relevant risk factors and the criteria for in-utero intervention, including goiter volume, amniotic fluid index, polyhydramnios and tracheal compression, we determined that hormonal therapy was warranted. Levothyroxine was injected every 7-10 days, and its efficacy monitored by ultrasound changes and amniotic hormone sampling.
Results: Reduction in goiter volume restored normal neck flexion relieving the pressure on the trachea, polyhydramnios was prevented and amniotic hormone levels were normalised. The infant was euthyroid at birth, however, by age 4 days hypothyroidism was diagnosed, and treatment with l-thyroxine started.
Conclusion: Advances in fetal ultrasonography permit judicious therapy of an enlarging goiter in a hypothyroid fetus, which may contribute to enhancing cognitive development. We discuss the value of amniotic hormone sampling, the objectives and risks of in-utero intervention in the light of recent literature and our own observations.