Severe Hyperemesis Gravidarum Masking the Presentations of Hyperthyroidism

Hyperemesis gravidarum may present with weight loss and tachycardia secondary to dehydration. Its severity correlates with the level of the serum chorionic gonadotropin which can interfere with the assay of the thyroid stimulating hormone. Therefore, hyperemesis gravidarum are at times difficult to be distinguished from hyperthyroidism. Missing hyperthyroidism during pregnancy results not only in inappropriate maternal care, but adverse neonatal outcomes including low birth weight. The authors report a case of hyperemesis gravidarum complicated by the concurrence of hyperthyroidism. Goiter and refractory tachycardia are the useful clues to detect occult hyperthyroidism in patients with hyperemesis gravidarum.