Ten Years' Experience of Antenatal Mean Corpuscular Volume Screening and Prenatal Diagnosis for Thalassaemias in Hong Kong

• Published in: The journal of obstetrics and gynaecology research 2000-06, Vol.26 (3), p.203-208
• Main Authors: Sin, S. Y., Ghosh, A., Tang, L. C. H., Chan, V.
• Format: Article
• Language: English
• Subjects: alpha-Thalassemia - blood; alpha-Thalassemia - diagnosis; antenatal MCV screening; beta-Thalassemia - blood; beta-Thalassemia - diagnosis; China; Erythrocyte Indices; Female; Humans; Pregnancy; Prenatal Diagnosis; thalassaemia
• ISSN: 1341-8076; 1447-0756
• DOI: 10.1111/j.1447-0756.2000.tb01312.x

Objective: To determine the prevalence of thalassaemia carriers in Hong Kong. Subjects and Methods: From 1988 to 1997, 25834 (53.7%) of 48089 mothers were screened for thalassaemias by mean corpuscular volume (MCV) at the first antenatal visit. Results: In the screened population of 25834, 2229 (8.6%) had MCV ≤ 75 fl. Of these, 1121 (4.3%) were α‐thal, 715 (2.8%) were β‐thal, 23 (0.1%) were αβ‐thal, 57 (0.2%) were other haemoglobin variants, and 281 (1.1%) had either iron deficiency or uncertain causes. Out of 200 pregnancies at risk for homozygous α‐thal‐1 and 32 at risk for β‐thal major, 27 homozygous α‐thal‐1 and 7 β‐thal major were identified, compared favourably with the expected figures of 23 and 9. Conclusion: Antenatal screening for thalassaemias by MCV is simple, effective and reliable. Universal screening has a different impact as bone marrow or cord blood stem cell transplant provides cure for β‐thal major. At risk couples have, as an alternative to termination of pregnancy, the option of early detection and treatment for their affected newborns or fetuses.