A 24-year-old primigravida at 20 weeks has haemoglobin 10.6 g/dL, MCV 64 fL, RBC count 6.2 million/mm3, RDW 13 percent, and serum ferritin 48 ng/mL. What is the most appropriate next step?

• A Start oral ferrous sulfate and repeat counts in 4 weeks
• B Reassure, as this represents physiological anaemia
• C Give a single infusion of ferric carboxymaltose
• D Perform haemoglobin analysis by HPLC or electrophoresis ✓

Explanation

A low MCV with a proportionately high RBC count gives a Mentzer index (MCV divided by RBC count) below 13, pointing to beta thalassaemia trait rather than iron deficiency. Ferritin is also normal, excluding iron lack. Iron therapy would be inappropriate and delays diagnosis, so confirmation requires haemoglobin fractionation by HPLC or electrophoresis. Physiological anaemia is normocytic, not microcytic with a raised red cell count.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.