Prenatal Diagnosis and Management of Fetal Goiter: A Case Series from Tertiary Perinatal Center in South India

Abstract

Aims and objectives: The reported incidence of fetal goiter is 1 in 40,000 live births. The effects of fetal goiter and thyroid dysfunction are significant. The objective of our study is to assess the safety, feasibility, and efficacy of intra-amniotic instillation of levothyroxine (LT4) in fetal goitrous hypothyroidism. Materials and methods: A retrospective observational study of prenatally diagnosed cases of fetal goiter on routine antenatal ultrasound between January 2010 and January 2018 at Fernandez Hospital Foundation, Hyderabad, tertiary perinatal referral center. Data retrieved from electronic database. Results: During this period, 9 cases of fetal goiter were diagnosed on routine ultrasonography with the incidence of 1 in 7,000 live births. The gestation age at diagnosis ranged between 21 weeks and 29 weeks (mean 26 weeks). Of the nine fetuses with goiter, two were excluded as one ended in a miscarriage at 22 weeks and the other was terminated elsewhere at 26 weeks. Data were analyzed in the remaining seven fetuses. Cordocentesis was performed in five fetuses and amniocentesis was performed in one woman with dichorionic diamniotic (DCDA) twin gestation which revealed hypothyroid status. Fetal therapy was offered to all the remaining seven fetuses with intra-amniotic instillation of LT4 100 to 200 μg at 2-3 weeks' interval. First dose of LT4 was given at mean gestation of 27 weeks (range 23-30 weeks), and the mean time between the identification of fetal goiter and the first dose of LT4 was 6 days (range 2-15 days). Number of injections given ranged between 1 and 7. No adverse events were recorded. Follow-up sonogram showed subjective reduction in the goiter size. All the babies had hypothyroidism at birth. Conclusion: Our case series confirms the safety and feasibility of intra-amniotic instillation of LT4 for fetal goitrous hypothyroidism. Although fetal therapy has resulted in reduction in the size of the goiter, the thyroid hormone levels at birth were low. Further research is required to establish the proper management guidelines for this disorder.