Flashcard · Maternal Anaemia
How is anaemia in pregnancy classified by red cell size (MCV)?
Answer
- Microcytic (low MCV): iron deficiency (commonest), thalassaemia, chronic disease
- Normocytic (normal MCV): physiological haemodilution, acute blood loss, anaemia of chronic disease, early iron deficiency
- Macrocytic (high MCV): folate deficiency (megaloblastic), vitamin B12 deficiency
Clinical relevance. Classifying anaemia by MCV directs the appropriate tests (ferritin, folate/B12, electrophoresis) and treatment.
More Detail
Classification of anaemia by MCV
The mean cell volume (MCV) is the practical first step in classifying anaemia.
Microcytic (low MCV)
- Iron deficiency - the commonest cause in pregnancy.
- Thalassaemia (consider if iron-unresponsive, normal/raised ferritin).
- Anaemia of chronic disease (can be normo- or microcytic).
Normocytic (normal MCV)
- Physiological haemodilution of pregnancy.
- Acute blood loss, anaemia of chronic disease, early iron deficiency.
Macrocytic (high MCV)
- Folate deficiency (megaloblastic - commonest macrocytic cause in pregnancy).
- Vitamin B12 deficiency (rarer).
Use
The MCV directs further tests (ferritin for microcytic; folate/B12 for macrocytic; haemoglobin electrophoresis if thalassaemia suspected).
Practise every Obstetrics & Gynaecology topic
This is a free sample. Sign up for the full bank of flashcards and exam-style questions on a spaced-repetition schedule, with 20 free stars a day.