A pregnant adolescent female is diagnosed with iron deficiency anemia and treated with elemental iron. To determine the effectiveness of the supplementation, the nurse practitioner instructs the adolescent to return:

Rationale: A. A complete blood count (CBC) includes multiple parameters, but for monitoring iron therapy specifically, hemoglobin and hematocrit are the primary indicators. B. Hemoglobin (Hgb) and hematocrit (Hct) levels should be rechecked approximately 4 weeks after starting elemental iron supplementation to assess for response to therapy and ensure that anemia is improving. C. Waiting 8 weeks is longer than necessary to detect an initial therapeutic response; early monitoring helps adjust dosing if needed. D. Serum ferritin reflects iron stores but is less commonly used for short-term monitoring of therapy response in pregnant adolescents. Hgb/Hct provide more immediate indicators of treatment effectiveness.