All women infected with HIV should have their haemoglobin A₂ (HbA₂) concentrations recorded before they start antiretroviral drug treatment to avoid later suspicion antenatally of heterozygous β thalassaemia trait and unnecessary genetic counselling and analysis, say some UK doctors. In their experience HbA₂ concentration can be raised solely by the treatment.

This is likely to become more of a problem now that universal antenatal screening for blood disorders is to be introduced to areas of the UK where β thalassaemia is prevalent and because more and more fertile women are being treated with antiretroviral drugs for HIV infection. A benchmark HbA₂ value will allow doctors to judge whether to exclude heterozygous β thalassaemia. …