Conservative Treatment of Fetal Goitrous Hypothyroidism Due to Thyroglobulin Mutations: A Case Report and Literature Review.

With the advances in fetal medicine, there will be more cases of congenital hypothyroidism (CH) diagnosed in the fetal period. However, there is no consensus on the management protocol. We present a successful case of conservatively managed fetal goitrous hypothyroidism due to compound heterozygous TG mutations. Goiter was observed in a fetus at 23 weeks of gestation. Because there was no evidence of transplacental passage of antithyroid antibody and drugs, iodine overload, and iodine deficiency, the fetus was highly suspected to have CH. Considering the potential risks of amniocentesis/cordocentesis, and lack of available parenteral levothyroxine in China, the fetus was closely monitored thereafter. A male neonate was delivered vaginally without complications at 39 weeks of gestation. We verified severe hypothyroidism in the infant and immediately initiated levothyroxine therapy. His growth and mental development were normal at the age of 8 month. Whole-exome sequencing showed that the neonate had two compound heterozygous mutations in the TG gene. We also performed a literature review of the prognosis of postnatal treatment of CH due to TG mutations and the result showed that postnatal treatment of CH due to TG mutations has a favorable prognosis. However, further prospective studies are warranted to verify this conclusion.