Prevention and control of thalassemia at Saraburi Regional Hospital

To evaluate the program in prevention and control of thalssemia among pregnant women and their spouses, prevention of new cases by screening tests, confirmatory test, genetic counselling, prenatal diagnosis, and selective abortion.

The pregnant women, attending antenatal care unit, Saraburi center hospital, as well as their spouses. 1 January 2000-31 December 2001

As part of the antenatal care assessment, pregnant women before 16 weeks gestation were screened, with pre- and post-test counselling, by osmotic fragility (OF) and dichorophenol indophenol precipitate (DCIP) tests, and confirmed by complete blood count (CBC), mean corpuscular volume (MCV), hemoglobin typing and polymerase chain reaction for alphathal1 (PCR alphathal1) if any of two screening tests was positive. The husbands of those who were carriers of severe thalassemia were encouraged to have thalassemia screening and confirmation. When both the pregnant women and their husbands were carriers of severe thalassemia, the pregnant women would voluntarily perform the prenatal diagnosis. Termination of pregnancy would be offered when the fetus had severe thalassemia.

There were 3,739 from 4,214 women (88.7% of all antenatal women), who participated in the program. OF and/or DCIP were positive in 1,742 of 3,739 subjects (46.5%). Of those, 960 from 1,742 (55.1%), had husbands who were willing to have the testing, and OF and/or DCIP were positive in 443 of 960 cases (46.1%). The confirmatory tests revealed carrier and disease of thalassemia, and hemoglobinopathies in 931 of 1,742 women (53.9%), and 135 of 960 husbands (14.0%). The 20 couples who had the possibility of having severe thalassemic newborns, were strongly advised to have prenatal diagnosis. The 12 risk pregnancies had been performed cordocentesis. Finally 3 of 12 (25.0%) fetuses were documented to have severe thalassemia and all of them decided to have selective abortion.

The screening model for thalassemia carriers by using the combination of OF and DCIP is the easy screening model. It can be done quickly, it is inexpensive, therefore it is suitable for large numbers of population screening. The systematic screening, confirmatory of thalassemia diagnosis and prenatal diagnosis are the measure of thalassemia prevention and control, and aims to decrease the number of newborns with severe thalassemia.