What is the normal range for nuchal fold thickness?
The normal range of NT for this age is 1.6-2.4 mm. Nuchal skin fold (NF) measurements and prenatal follow-up ultrasound findings were normal. A Triple test was performed, and it showed a positive result and a high risk of trisomy 21.
What is nuchal skin fold?
The nuchal fold (NF) thickness is a measurement performed on prenatal ultrasound, and is the distance from the outer edge of the occipital bone to the outer edge of the skin in the midline.
What is a normal nuchal fold measurement at 21 weeks?
The generally accepted upper limit for nuchal fold thickness up to 20 weeks’ gestation is 6 mm. Some authors have suggested that decreasing the cutoff to define a thick nuchal fold to 5 mm would increase the sensitivity for detection of trisomy 21.
What is the normal neck thickness 12 weeks?
At 12 weeks of gestational age, an “average” nuchal thickness of 2.18mm has been observed; however, up to 13% of chromosomally normal fetuses present with a nuchal translucency of greater than 2.5mm.
What does nuchal fold mean in pregnancy?
The nuchal fold is a normal fold of skin seen at the back of the fetal neck during the second trimester of pregnancy. Increased thickness of the nuchal fold is a soft marker associated with multiple fetal anomalies, and is measured on a routine second trimester ultrasound.
What are the chances of Down syndrome if NT scan is normal?
For example, a risk of 1 in 100 means that for every 100 women with this result, one baby will have Down syndrome and 99 will not. A risk of 1 in 1,200 means that for every 1,200 women with this result, one baby will have it and 1,199 will not.
How thick should nuchal fold be at 20 weeks?
Comparison of nuchal skin fold thickness (NFT) in a normal 20-week fetus on the standard horizontal transcerebellar and 30° occiput images. (a) The standard horizontal transcerebellar image of a normal 20-week fetus gives a NFT measurement of 6.5 mm.
What should the nuchal fold be at 20 weeks?
All babies have a small pad of tissue at the back of the neck; this is called the nuchal fold (NF). The nuchal fold normally measures less than 6mm at 20 weeks.
What is a good NT scan result?
What is a normal nuchal translucency measurement? An NT of less than 3.5mm is considered normal when your baby measures between 45mm (1.8in) and 84mm (3.3in) . Up to 14 weeks, your baby’s NT measurement usually increases as they grow.
What is normal NT scan result?
Can nuchal fold measurement be wrong?
The objects were used by participating healthcare centers and involved 18 operators and 23 machines. This study found that there was a systematic error of about 0.5 mm in the accuracy of the nuchal translucency measurement overall.
How accurate is nuchal fold test?
NT results by themselves have an accuracy rate of about 70 percent. That means that the test misses 30 percent of babies with Down syndrome or other chromosome disorders. Including the NT as part of a first trimester combined screening improves detection to between 83 and 92 percent.
How accurate is the nuchal fold measurement?
How accurate is nuchal translucency? NT results by themselves have an accuracy rate of about 70 percent. That means that the test misses 30 percent of babies with Down syndrome or other chromosome disorders.