Background: The accuracy of diagnosis reported in multiple large series has pushed both screening and diagnostic testing for chromosomal disorders to the window now refe (nuchal translucency scan).11-13+6 weeks scan shows normal foetal anatomy and identifies severe structural problems. Early detection of these problems allows for safer and easier pregnancy termination. Tests include chorionic villous sampling and amniocentesis carry a 1% foetal loss risk. So non- invasive screening tests are required.first trimester screening is a new non-invasive technique that combines maternal blood screening and foetal screening to discover chromosomal abnormalities (including trisomy 21).Because there are few studies in this field, the current study aims to investigate the utility of high resolution ultrasound as a screening test for aneuploidy risk in late first trimester foetuses. Objectives :1. Assess the utility of ultrasound as a screening tool for foetal first trimester aneuploidies.2. Ultrasound to identify aneuploidy- prone foetuses.3. To establish the use of ultrasonography in regular first trimester screening. Materials and Methods: This research performed at Vydehi Institute of Medical Sciences Hospital and Research Centre studied 220 pregnant ladies. Present study investigated increased nuchal translucency and foetal abnormalities.