Abnormal circulating androgen level Decreased gonadotropin-stimulated testosterone-to-androstenedione ratio 2021-01-15T12:34:18Z Decreased plasma testosterone-to-androstenedione ratio A reduced amount of testosterone relative in androstenedione in the blood circulation following administration of hCG (Human Chorionic Gonadotropin). Androstenedione is made in the adrenal glands as well as the testes and ovaries. In females, androstenedione is converted to provide around half of all testosterone and almost all estrone. In males, androstenedione is produced by the testes and rapidly converted to testosterone. A low testosterone:androstenedione ratio following hCG stimulation may be a useful method of diagnosing 17beta-hydroxysteroid dehydrogenase-3 (17 betaHSD3) deficiency.