Introduction: The incidence of fetal goiters is reported to be around 1 per 40,000 births. The risk of complications is first of all obstetric, directly related to goiter size, but it may also affect longer term fetal and child development, depending on whether the goiter is due to hypo- or hyperthyroidism. Management is multidisciplinary, but not yet consensual and not always optimal by either endocrinologists or obstetricians.Objectives: The principal objective of this retrospective study was to analyze the data that enabled the physicians to assess whether the goiter was hypo- or hyperthyroid and then to analyze the obstetric practices used in the Pays de Loire network to describe in detail the tools used to diagnose and characterize the goiters and the management chosen in these cases. The secondary objectives are to assess, in our small cohort, the effectiveness of the in utero treatments provided, based on the examination of the children at birth and their outcome at 6 months of life, and to suggest a strategy for monitoring these women at risk that takes current guidelines into consideration.Materials and methods: This multicenter retrospective study covers a 6-year period and focused on the prenatal diagnosis centers (CPDPN) of the Pays de Loire perinatal network: in Nantes, Angers, and Le Mans. The network is responsible for around 42,000 births a year, and the study included 17 women, for a prevalence of 1 per 15,000 births.Results: Ten of the 17 fetuses had a hypothyroid goiter, 4 a hyperthyroid goiter, and 3 normal thyroid findings on fetal blood sample (FBS). For four women, these goiters were secondary to fetal dyshormonogenesis, for 9 more to Graves disease with TSH receptor antibodies (TRAb), and for four women to thyrotoxicosis at the start of pregnancy, managed by synthetic antithyroid drugs. Two newborns had severe complications associated with maternal transmission of Graves disease (TRAb positive at birth): one with exophthalmos and one with neonatal tachycardia. The other 14 had normal psychomotor development at 6 months, based on a clinical examination by a pediatric endocrinologist; only one child was lost to follow-up.Conclusion: Together, ultrasound and multidisciplinary expertise (of an endocrinologist and an obstetrician experienced with this disease) remain the best means for avoiding, or otherwise for accurately characterizing fetal goiter. An ultrasound diagnostic score, of the type proposed by Luton et al. in 2009, may make it possible to homogenize practices and thus to defer or delay the - currently too common - performance of invasive FBS procedures, which must remain rare in this management to limit comorbidities. A threshold TRAb value (>5 IU/l) makes it possible to define this group of women as at risk of fetal and neonatal hyperthyroidism and thus requiring close monitoring. The value of prenatal intra-amniotic thyroxine treatment for hypothyroid goiters (including dyshormonogenesis) remains to be demonstrated.
Keywords: Dyshormonogenesis; Graves disease; TRAb; fetal goiter; hyperthyroidism; hypothyroidism.