AbstractPurpose of review
This review provide an update on antenatal screening and diagnosis of thalassaemia disorders.Recent findings
The topics covered are the effectiveness of antenatal screening programmes for thalassaemia, its prenatal diagnosis, molecular basis and laboratory findings, ultrasound screening for haemoglobin Bart's disease, and non-invasive prenatal diagnosis of thalassaemia.Summary
Universal antenatal screening for thalassaemia carriers should be implemented in populations with a high prevalence of this condition. The appropriate measure to screen for α and β thalassaemias remains mean cell haemoglobin (<27 pg) or mean corpuscular volume (<80 fl). A haemoglobin pattern and iron profile should follow if the red cell indices are low. In a population where α thalassaemia is prevalent, it is advisable to check the partner's mean cell haemoglobin or mean corpuscular volume as well. Further cascades of investigations will depend on these results and the prevalence of other haemoglobinopathies in that population. Invasive prenatal diagnosis remains the gold standard for diagnosis in high-risk couples. Provided expertise is available, ultrasound measurement of the cardiothoracic ratio appears a good screening tool for α thalassaemia major. Non-invasive prenatal diagnosis by identification of a paternal mutation in maternal plasma, although currently at the experimental stage, may be an option in the future.