Objective: To investigate the relationship between two novel first-trimester ultrasound markers (abnormal fetal ductus venosus [DV] flow and presence of tricuspid regurgitation [TR]) and the results of the first-trimester combined screening test in pregnancies with a normal karyotype. The screening test involves nuchal translucency measurement by ultrasound, and measurement of serum free beta-chorionic gonadotropin and pregnancy-associated plasma protein A