Foetal goitrous hypothyroidism - easy to recognise, difficult to treat. Is combined intra-amniotic and intravenous L-thyroxine therapy an option?

INTRODUCTION

Foetal hypothyroidism negatively impacts somatic and neurological child development and can be the cause of serious obstetric and perinatal complications. We present a rare case of a large foetal dyshormonogenetic goitre, causing foetal neck hyperexten-sion, oesophageal compression, and cardiac high-output failure.

MATERIAL AND

METHODS

A foetal goitre complicated by cardiomegaly and polyhydramnios was diagnosed at 23 weeks of gestation (WG) on a routine ultrasonographic (US) assessment in a healthy nullipara. Foetal blood sampling was performed and a severe foetal hypothyroid-ism was diagnosed. Treatment was undertaken with an intra-amniotic followed by combined intra-amniotic and intravenous injections of L-thyroxine (L-T4). A total of 11 doses of L-T4 were administered between 24-37 WG to the foetus.

RESULTS

A complete regression of foetal goitre, cardiomegaly, and polyhydramnios was observed. At 38 WG the patient delivered vagi-nally a male infant with mild hypothyroidism and no signs of goitre or cardiomegaly on postnatal US. Neurological development of the one year old baby is normal.

CONCLUSIONS

The effective diminishing of serum TSH concentration and goitre size was reached after combined intra-amniotic and in-travenous L-T4 injections were given. L-T4 requirement in the foetus is equal to or above 15 μg/kg daily and should be given in weekly intervals due to its rapid metabolism by the foetus and by placental type 3 deiodinase. Intra-amniotic L-T4 administration may be inef-fective when a large goitre indisposes amniotic fluid swallowing by the foetus, so then the combined L-T4 injections into the umbilical vein and intra-amniotically in experienced hands seems to be a reasonable and effective option.