Radioiodine treatment in unsuspected pregnancy

Abstract

Objective: Radioiodine is being used increasingly as first line therapy for hyperthyroidism. Our aim is to highlight some of the difficulties which can occur following the use of 131I to treat hyperthyroidism in fertile women.

Patients: We present 3 cases of young women to whom radioiodine was given, only to find some weeks later that they had been pregnant at the time of treatment.

Conclusions: These cases serve as a reminder of the importance of obtaining an accurate and full menstrual and contraceptive history. Guidelines advocate the application of the ten day rule with the further recommendation that pregnancy testing may be undertaken as an alternative.