ABSTRACT
PURPOSE: To determine the prevalence and screening performance for detection of Down syndrome of fetal tricuspid regurgitation in the second trimester of pregnancies at risk for fetal chromosomal defects. METHODS: A prospective study was carried out on pregnant women at risk for fetal chromosomal defects who had amniocentesis or cordocentesis for fetal karyotyping at 16 to 23 weeks' gestation, between February 2017 and January 2018. An assessment of the fetal tricuspid valve was conducted before any invasive procedure. Tricuspid regurgitation was defined as flow reversal for at least half of systole, with a maximum velocity of ≥100 cm/s. RESULTS: In the 486 cases studies, fetal tricuspid regurgitation was found in 21 (4.3%), and 10 fetuses had Down syndrome. The tricuspid regurgitation was found in 15 (3.2%) of the 462 euploid fetuses, in 5 (50%) of the Down syndrome fetuses, and in 1 (7.1%) of the fetuses with other chromosome abnormalities. Tricuspid regurgitation was found as an isolated marker in 2 of the 10 Down syndrome fetuses. The sensitivity, specificity, positive predictive value, and negative predictive value to screen for Down syndrome were 50%, 96.8%, 25%, and 98.9%, respectively. CONCLUSIONS: Tricuspid regurgitation showed a high prevalence in fetal Down syndrome at the gestational age of 16 to 23 weeks and was an isolated marker in 20% of them.
