Endocrine Abstracts

JOINT581

Introduction: Clinical hyperthyroidism in the first trimester of pregnancy secondary to Graves’ disease can lead to maternal, obstetric and fetal complications requiring appropriate treatment to restore euthyroidism. Because of fetal malformations reported after treatment with carbimazole/methimazole during gestation, treatment of Graves’ hyperthyroidism in pregnancy should be based on propylthio-uracil (PTU) during the first trimester, followed by carbimazole/methimazole during the second and third trimesters of pregnancy.

Observation: A 40-year-old female patient with no previous medical history, consulted for management of clinically and biologically confirmed Graves’ disease -already on treatment-, in the third month of pregnancy. Given that PTU was not available, and the hyperthyroidism was well tolerated, simple clinical and biological monitoring was decided for her. The pregnancy progressed correctly and the delivery was normal and uneventful. The child was male, in good general condition and without any malformations. After delivery, the patient was put back on antithyroid treatment and underwent total thyroidectomy.

Discussion: Subclinical or moderate thyrotoxicosis may improve during pregnancy (increase in TBG, decrease iodine pool, immune tolerance status) and does not require treatment in pregnant women. In this patient with Graves’ disease treated with synthetic antithyroid drugs before pregnancy, euthyroidism was maintained without treatment during pregnancy, but a recurrence of the disease occurred after delivery, requiring radical treatment, illustrating the immune tolerance favoured by the pregnant state.