Tapering Levothyroxine Dose for Intra-Amniotic Infusion in the Antenatal Treatment of Fetal Goiter: A Case Report.

Fetal goitrous hypothyroidism is associated with important obstetrical complications including preterm birth, polyhydramnios, respiratory disorders, and neurodevelopmental impairments. There are currently no standard treatment guidelines for fetal goitrous hypothyroidism, and further studies are needed to help establish treatment guidelines. We report a case of a healthy 41-year-old female whose fetus was diagnosed with fetal goiter at 20 weeks gestation. The patient underwent weekly intra-amniotic infusions of levothyroxine, and the fetal goiter resolved by 30 weeks gestation. The infant was delivered vaginally at 36 weeks with no evidence of goiter on physical exam and diagnosed with congenital hypothyroidism upon follow-up with pediatric endocrinology. Both mother and infant are doing well today with the infant showing no signs of neurodevelopmental impairment. This case demonstrates that intra-amniotic infusion of levothyroxine for fetal goiter may improve perinatal outcomes.