First trimester sonographic mcnsuremenl of nuchnl translucency (NI) is widely practiced in many yountrics far screening of Down syndrome. trisonly II Maternal age, several scoomaphic and Doppler parameters, and maternal serum biochemistry have been included in foetal anceploidy screening programer to impmve the rates of deterDming foetal NT screening ultrasonography is used to assess for a Fluid collection at the nape of the foetal neck. An abnormal fluid collection may be related to genetic disorders and/or physical anomalies. This screening is most accurate when performed between 10 and 14 weeks gestadon. Both transabdominal and trunsvuginal scanning can be used to measure foetal NT. A mid-septet section of the foams should be obtained and the NT should be measured with she foetus in Mc neusral position (Figurel). The magnification should be or large m possible and only she foetal head and upper thorax should be included in the image. Measurement is taken at she thickest region of the subcutaneous translucency between the skin and the soh tissue overlying the cervical spine.