Summary: We report the case of a 37-year-old woman who presented with hyperemesis gravidarum at 11 weeks of gestation. Laboratory examination revealed severe thyrotoxicosis (TSH: 200 ng/mL; reference range:, <33.7 ng/mL) were also compatible with a possible contribution from painless thyroiditis (PT). Serum hCG levels normalized after the second trimester. Recurrent and sustained thyrotoxicosis during pregnancy across multiple pregnancies in the same patient is rare and requires careful differentiation among possible etiologies, including GTT, GD, and PT. This case underscores the importance of comprehensive monitoring of placental function, thyroid autoimmunity, and thyroiditis throughout pregnancy to ensure accurate diagnosis and tailored management for both mother and fetus. Learning points: The diagnosis of recurrent thyrotoxicosis in pregnancy is complex, as distinct entities can overlap clinically. Comprehensive phenotyping - incorporating thyroid autoantibodies, serum hCG, Tg, and ultrasound - guides diagnosis; reserve TSHR testing for atypical or persistent cases. Careful longitudinal monitoring across pregnancies enables optimized maternal-fetal outcomes.
Kaido et al. (Wed,) studied this question.