Cardiac blood flow studies in fetuses with homozygous α‐thalassemia‐1 at 12–13 weeks of gestation

Abstract

Objective Fetuses affected by homozygous α-thalassemia-1 develop anemia as early as the first trimester. Our objective was to study hemodynamic indices in affected fetuses at 12-13 weeks of gestation to determine whether these would be useful in the prediction of anemia.Design Prospective observational study. Subjects

Ductus venosus Doppler study in fetuses with homozygous α‐thalassemia‐1 at 12 to 13 weeks of gestation

“…Because the α-globin-dependent hemoglobin F is the major fetal hemoglobin from 8 weeks of gestation 1 , fetuses affected by homozygous α-thalassemia-1 are anemic from the first trimester of pregnancy. We have confirmed previously that these affected fetuses have a similarly low hemoglobin concentration at 12-13 weeks to that in later gestation 2 . The disease represents a unique model of fetal anemia that starts in the first trimester of pregnancy.…”

Nuchal translucency in fetuses affected by homozygous α‐thalassemia‐1 at 12–13 weeks of gestation

“…Fetuses affected by homozygous α-thalassemia-1 have deficient α-globin chain production. Their hemoglobins consist primarily of hemoglobin Bart's and hemoglobin Portland instead of hemoglobin F. These fetuses are anemic from the first trimester of pregnancy and their hemoglobin concentrations range from 4 to 8 g/dl at 12-13 weeks of gestation 2 . The disease provides a unique model for the study of fetal physiological responses to anemia in the first trimester.…”

Prenatal diagnosis of haemoglobin Bart's disease by cordocentesis at 12-14 weeks?experience with the first 59 cases

“…The cardiac output increases by the Frank± Starling mechanism. Doppler studies of the affected fetuses show a three-fold increase in cardiac output at 18±20 weeks (Ghosh et al, 1994) and a one-third increase at 12±13 weeks (Lam et al, 1999a). Sonographic measurement of the cardiothoracic ratio is a simple method to detect fetal cardiac enlargement.…”

“…Each year around 100 athalassaemia-1 couples are referred to our unit for prenatal diagnosis of haemoglobin (Hb) Bart's disease (Lam and Tang, 1998). Prenatal diagnosis is indicated because the affected fetuses are severely anaemic since the ®rst trimester of pregnancy (Lam et al, 1999a) and they often die before or shortly after birth. Women carrying affected fetuses have a high chance of developing life-threatening obstetric complications in the third trimester (Liang et al, 1985).…”