What is the normal range for nuchal translucency measurement?

The normal range for nuchal translucency measurement is considered to be less than 3 mm. Nuchal translucency refers to the fluid collection at the back of the fetal neck and is measured through ultrasound during the first trimester, typically between 11 to 14 weeks of gestation. A measurement less than 3 mm is generally interpreted as being within the normal range and is associated with a lower risk of chromosomal abnormalities, particularly Down syndrome.

Through prenatal screening, the nuchal translucency measurement, along with other factors such as maternal age and blood test results, helps to assess the risk of trisomies and other genetic conditions. A reading above this threshold may suggest a higher risk and could prompt further diagnostic testing, such as chorionic villus sampling or amniocentesis, to rule out potential abnormalities.

Understanding the significance of this measurement is important for both patient counseling and clinical decision-making.