Thalassaemia screening in pregnancy.
OBJECTIVE
This review provide an update on antenatal screening and diagnosis of thalassaemia disorders.


RESULTS
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.


CONCLUSIONS
Universal antenatal screening for thalassaemia carriers should be implemented in populations with a high prevalence of this condition. The appropriate measure to screen for alpha and beta 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 alpha 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 alpha 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.
Leung
Tse N
TN
Academic Division of Obstetrics and Gynaecology, The University of Nottingham, The Medical School, Derby City General Hospital, Derby, UK. dannytnleung@cuhk.edu.hk
Lau
Tze K
TK
Chung
Tony Kh
TKh
D004909:Erythrocyte Indices; D005260:Female; D005315:Fetal Diseases / Q000097:blood / Q000175:diagnosis; D006400:Hematocrit; D006403:Hematologic Tests; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D008403:Mass Screening; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic; D011256:Pregnancy Outcome; D011296:Prenatal Diagnosis / Q000379:methods; D013789:Thalassemia / Q000097:blood* / Q000175:diagnosis*; D017085:alpha-Thalassemia / Q000097:blood; D017086:beta-Thalassemia / Q000097:blood / Q000378:metabolism
D006454:Hemoglobins