Determination of the Need for Prenatal Diagnosis in Carriers of Alpha Thalassemia

In recent years, both alpha and beta thalassemia have been screened in couples before marriage. The severe form of alpha thalassemia, i.e. hydrops fetalis, is found in fetuses and causes fetal death. We tried to determine the need for prenatal diagnosis of hydrops fetalis among couples referred to Alzahra Genetic Laboratory. We also evaluated the cost-effectiveness of alpha thalassemia screening. This descriptive study included all individuals that had been referred to the genetic laboratory from various health centers in Isfahan (Iran). The subjects had mean corpuscular volume less than 80 fL, mean corpuscular hemoglobin less than 27 pg, and hemoglobin A2 less than 2.5. Moreover, one month of iron supplementation had failed to normalize their blood indexes. DNA was duplicated with polymerase chain reaction and examined with gel electrophoresis. During the 27 months and nine days of the study (2009-2012), 642 eligible couples were referred to Alzahra Genetic Laboratory. Of these, 75 couples (11.6%) had beta-beta genotype, 343 couples (53.4%) had alpha-alpha genotype, and 224 couples (34.8%) had genotype alpha-beta. Of the 343 couples who had alpha-alpha genotype, three couples (0.87%) required to have prenatal diagnosis. Considering the very few fetuses that required prenatal diagnosis, the cost-effectiveness of alpha-thalassemia screening in preparing couples for marriage has to be further evaluated at the country level. On the other hand, as fetuses with hydrops will not survive and will abort (only one fetus had hydrops in this study), children with thalassemia major will not be a problem.