In pregnancy, Addison's disease is treated with which glucocorticoid replacement?

• A. Hydrocortisone
• B. Fludrocortisone
• C. Prednisone
• D. Dexamethasone

Answer: (A)

Hydrocortisone is used because it is physiologic cortisol, providing the necessary glucocorticoid effect while also contributing some mineralocorticoid activity to help with salt and fluid balance. In pregnancy, this agent closely mimics the body's normal cortisol production and has a safety profile that is favored for both mother and fetus. Fludrocortisone addresses mineralocorticoid deficiency but does not supply the needed glucocorticoid effect. Prednisone and dexamethasone are also glucocorticoids, but dexamethasone crosses the placenta readily and is not preferred for routine maternal replacement, while prednisone is largely inactivated by the placenta to prednisolone, altering fetal exposure. So, hydrocortisone is the best choice for glucocorticoid replacement in pregnancy with Addison’s disease.