<prompt> Nuchal translucency is measured between8 to 10 weeks11 to 14 weeks16 to 18weeks18 to 20weeks  <response>: Nuchal translucency represents the maximum thickness of the subcutaneous translucent area between the skin and soft tissue overlying the fetal spine at the back of the neck. It is measured in the sagittal plane between 11 and 14 weeks using precise criteria. Increased NT is seen inChromosomal abnormalitiesGenetic SyndromesCardiac anomaliesSkeletal deformitiesRef: Williams Obstetrics; 25th edition 