Question: what is normal nt range?
Answer: The average NT thickness was 1.7 mm (range from 0.9 mm to 13.4 mm). The NT was above the 95th centile of the normal range for the CRL in 75% (15 out of 20) of trisomy 21 pregnancies and in 64% (16 out of 25) pregnancies with other chromosomal abnormalities.