What postpartum diuresis occurs, and why?

• A. Rapid diuresis due to mobilization of excess extracellular fluid and hormonal changes, leading to edema resolution
• B. Diuresis due to dehydration from labor
• C. Diuresis occurs only after 6 weeks
• D. Diuresis is unrelated to postpartum changes

Answer: (A)

Postpartum diuresis is the rapid loss of extracellular fluid accumulated during pregnancy, helping edema resolve. After delivery, placental hormones drop quickly, reducing fluid retention, and some of the interstitial fluid shifts back into the bloodstream. The kidneys then excrete this surplus as brisk urine output, often starting in the first day or two after birth and continuing for several days. This combination of fluid mobilization and hormonal changes trims edema as the body returns to its nonpregnant state. It’s not due to dehydration from labor, it doesn’t wait until 6 weeks postpartum, and it is closely tied to postpartum hormonal and fluid shifts.