Use of anti-thyroid drugs in euthyroid pregnant women with previous Graves' disease.

PURPOSE: Euthyroid pregnant women with a previous history of Graves' disease treated with radioiodine or surgery may have persistently elevated TSH receptor antibody (TRAb) levels, putting their offspring at risk for fetal hyperthyroidism (FH) and/or neonatal hyperthyroidism (NH). METHODS: We performed a literature review using a MEDLINE search to determine if and how anti-thyroid drugs (ATD) were utilized in euthyroid pregnant women with previous Graves' disease to prevent FH/NH. RESULTS: There are 11 published reports involving 13 pregnancies where ATDs were utilized to prevent FH in euthyroid mothers with a previous history of Graves' disease. Subjects were treated if high titres of TRAb (> 5-fold above normal) were noted on either radioreceptor assay or various bioassays. Such intervention appeared beneficial. Thirteen live births were observed when previously these mothers collectively experienced six miscarriages, stillborn or infant deaths attributed to FH or NH. Developmental consequences such as craniosynostosis or dysmorphic features were not observed in the infants described. Both propylthiouracil and methimazole were used effectively. When utilized, cordocentesis (or periumbilical blood sampling) to determine fetal thyroid status and TRAb levels proved to be of value in establishing the diagnosis and guiding therapy. CONCLUSION: Maternal ATD prevent the serious consequences of FH/NH and should be considered for euthyroid Graves' mothers with high TRAb titres.