A 24-year-old primigravida at 30 weeks presents with fatigue and glossitis. Haemoglobin is 8.0 g/dL, MCV 108 fL, and peripheral smear shows hypersegmented neutrophils and macro-ovalocytes. She is a strict vegan. Serum vitamin B12 levels are normal. The MOST likely cause of her anaemia is:
- A Vitamin B12 malabsorption
- B Folate deficiency ✓
- C Mixed iron and B12 deficiency
- D Myelodysplastic syndrome
Correct answer: B. Folate deficiency
Explanation
Megaloblastic anaemia in pregnancy is almost always due to folate deficiency because fetal and placental demands triple maternal folate requirements, and the increased demand is unmasked by poor dietary intake. Normal serum A12 with macrocytosis, hypersegmented neutrophils and glossitis points to folate deficiency. A12 deficiency is the best distractor, but a documented normal A12 level excludes it, and myelodysplasia is rare at this age without other cytopenias.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.