Ten years' experience of antenatal mean corpuscular volume screening and prenatal diagnosis for thalassaemias in Hong Kong.
OBJECTIVE
To determine the prevalence of thalassaemia carriers in Hong Kong.


METHODS
From 1988 to 1997, 25,834 (53.7%) of 48,089 mothers were screened for thalassaemias by mean corpuscular volume (MCV) at the first antenatal visit.


RESULTS
In the screened population of 25,834, 2229 (8.6%) had MCV < or = 75 fl. Of these, 1121 (4.3%) were alpha-thal, 715 (2.8%) were beta-thal, 23 (0.1%) were alpha beta-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 alpha-thal-1 and 32 at risk for beta-thal major, 27 homozygous alpha-thal-1 and 7 beta-thal major were identified, compared favourably with the expected figures of 23 and 9.


CONCLUSIONS
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 beta-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.
Sin
S Y
SY
Department of Obstetrics and Gynaecology, Kwong Wah Hospital, Hong Kong, SAR China.
Ghosh
A
A
Tang
L C
LC
Chan
V
V
D002681:China; D004909:Erythrocyte Indices; D005260:Female; D006801:Humans; D011247:Pregnancy; D011296:Prenatal Diagnosis; D017085:alpha-Thalassemia / Q000097:blood / Q000175:diagnosis*; D017086:beta-Thalassemia / Q000097:blood / Q000175:diagnosis*