(Using fetal nuchal translucency to screen for major congenital cardiac defects at 10 - 14 weeks of gestation: population based cohort study)
In fetuses, identifying increased nuchal translucency thickness by ultrasound scan at 10 - 14 weeks of gestation reveals the majority (55 per cent) of major defects of the heart and arteries, according to a study in this week's BMJ. Dr Jon Hyett and colleagues from King's College Hospital Medical School and Guy's Hospital in London report that this method of screening is more accurate than the traditional method of viewing the four chambers of the fetal heart at 16 - 26 weeks, which only picks up a quarter (26 per cent) of major defects.
In the fetus, fluid collects behind the neck and this can be measured by ultrasound scanning - the more fluid that has accumulated the thicker the nuchal translucency and the greater the risk of an abnormality being present. In their study of 29,154 pregnancies, the authors report that 50 (1.7 per 1000) involved a fetus with a major heart defect.
Hyett et al recommend that fetuses identified as having increased nuchal translucency should be referred for specialist fetal echocardiography.
Professor Kypros Nicolaides, Harris Birthright Research Centre for Fetal Medicine, Department of Obstetrics and Gynaecology, King's College Hospital Medical School, London
Contact: Jill Shepherd
BMJ-British Medical Journal