Nomograms of fetal nuchal fold thickness for early detection of down syndrome

A prospective study was undertaken in North India to find the normative data on the nuchal fold thickness of randomly selected 150 fetuses between 16–22nd week of gestation. The data revealed that the width of nuchal fold thickness ranged between 2–5mm. The mean for 16–18, >18–20, and >20–22 week's gestation was 2.6±0.2, 3.8±0.9, and 4.0±0.8 mm respectively. In one fetus nuchal fold thickness was 6mm at 18 weeks (>2SD above the normal value) and thus Down Syndrome was suspected. This was later confirmed by amniocentesis and karyotyping.