Prenatal diagnosis of homozygous α-thalassemia: From an invasive to a noninvasive approach

Abstract

The birth of babies with homozygous α-thalassemia can be prevented by prenatal screening and diagnosis. Serial ultrasound examination of fetal cardio-thoracic ratio and placental thickness can exclude an affected pregnancy and, thus, reduce the need for an invasive test. Whether middle cerebral artery Doppler is useful in the prediction is not clear. 3D ultrasound examination, maternal blood-smear screening for fetal hemoglobin Barts cells and maternal serum markers for Down syndrome have also been investigated. In view of the recent data on the survival of affected fetuses after in utero transfusion, it is arguable whether the latter should be offered as an alternative to termination of pregnancy after prenatal diagnosis. Preimplantation genetic diagnosis is possible, particularly for couples with repeatedly affected pregnancies. © 2009 Expert Reviews Ltd.