Synopsis
Select and interpret haemoglobin analysis in context, recognise assay and transfusion limitations, confirm consequential variants molecularly, and translate paired results into non-directive reproductive counselling.
- Modern laboratories use high-performance liquid chromatography, capillary electrophoresis, isoelectric focusing or complementary methods; the report must be interpreted with method, age and clinical question.
- Adult haemoglobin A predominates normally, with small HbA2 and HbF fractions; newborns predominantly express HbF, so infant patterns use different algorithms.
- Raised HbA2 supports beta-thalassaemia trait, but iron deficiency, transfusion, delta-chain variants and coexisting haemoglobin variants can alter the result.
Key red flags
A pregnant carrier whose partner is untested needs prompt screening coordination so fetal-risk assessment and options are not delayed.
Investigation priorities
Provide globin-production context for the fraction pattern.
Management branches
Microcytosis, haemolysis, family history, pregnancy or newborn screening raises haemoglobinopathy.
- Provide age, pregnancy, transfusion date, hydroxycarbamide exposure, full count and iron status to the accredited laboratory.
- Use quantitative haemoglobin separation rather than a solubility screen for carrier or disease classification and retain any pre-transfusion sample.