Life-threatening fetal goiter: diagnosis and outcomes in four consecutive cases with critical appraisal-why this diagnosis is not obviously trivial.

BACKGROUND: The diagnosis of a fetal goiter constitutes a potentially life-threatening in utero condition for the fetus. Even with early diagnosis and close therapy with highly specialized interdisciplinary management, the prognosis remains poor. We discuss diagnostic and therapeutic challenges regarding the pre- and postnatal outcome based on four consecutive cases with a critical appraisal of latest heterogeneous recommendations in literature. METHODS: A retrospective review of four cases of fetal goiter is presented that were diagnosed at a tertiary university centre during targeted ultrasound (US) examination in second and third trimester. All cases underwent close and intensive pre- and postnatal diagnostics and treatment. A detailed workup of current diagnostic and therapeutic recommendations with identifying potential pitfalls was carried out. CASE SERIES: In one case, the mother suffered from Graves' disease with euthyroid blood parameters under medication. The other three gravidae largely had an uneventful medical history including euthyroid metabolism. In all cases, fetal hypothyroidism was suspected and in three of them, cordocentesis was performed and intraamniotic levothyroxine (LT4) was given. In none of the cases, sonographic signs of tracheoesophageal compression had been noticed. In all four cases, a planned cesarean section was performed between 32 and 39 weeks of gestation (weeks). Out of all four cases, only one fetus managed to survive: one fetus died antenatally at 35 weeks, one newborn died due to insufficient ventilation, and one due to fetal cardiac decompensation with bilateral hydrothorax with suspected ductal obstruction. The fetus who survived showed primary hypothyroidism. Two of the deceased fetuses underwent autopsy, one showed ectopic thyroid tissue in the trachea. CONCLUSION: Prenatal diagnosis of congenital fetal goiter remains a serious condition in specialized centers. In practice, the following crucial considerations might impede proper application of the non-standardized recommendations suggested in available literature. In addition to the assessment of the underlying etiology, the evaluation of fetal cervical structures with determination of fetal tracheoesophageal patency and cardiac functional diagnostics requires adequate practical expertise. Interdisciplinary cooperation is mandatory when determining the time and mode of delivery and planning an ex utero intrapartum treatment (EXIT) strategy.