Can a thick nuchal fold be normal?
Can a thick nuchal fold be normal?
Many healthy babies have thick nuchal folds. However, there is a higher chance for Down syndrome or other chromosome conditions when the nuchal fold is thick. There may also be a higher chance for rare genetic conditions.
What is the normal nuchal fold thickness at 21 weeks?
Figure 2
| GA, wk | Patients, n | Nuchal Fold Thickness, mm |
|---|---|---|
| Mean ± SD | ||
| 20 | 2,241 | 4.29 ± 0.81 |
| 21 | 8,066 | 4.62 ± 0.78 |
| 22 | 10,240 | 4.78 ± 0.77 |
What does a thick nuchal fold indicate?
Abstract. Many studies have shown that a thickened nuchal fold in a second-trimester fetus is a sonographic sign suggestive of a high risk for Down syndrome. These series have included fetuses already at risk for aneuploidy because of advanced maternal age or abnormal maternal serum alpha-fetoprotein (AFP) levels.
What is the normal range for nuchal fold thickness?
The nuchal fold thickness is considered normal if under 5mm between 16 and 18 weeks gestation and under 6mm between 18 and 24 weeks gestation. An increased thickness corresponds to increased risk for aneuploidy and other fetal abnormalities.
When do you stop measuring nuchal fold?
Nuchal fold thickness of >6 mm is abnormal on a routine morphology ultrasound performed at 18-22 weeks. The nuchal fold is known to increase throughout the second trimester in a normal pregnancy, and may be measured during a broader window of 14 and 24 weeks when required.
What is an abnormal nuchal fold measurement?
ACOG defines an abnormal nuchal fold as ≥ 6mm in the 2nd trimester (typically performed between 15w0d and 22w6d). The SOGC (Society of Obstetricians and Gynecologists of Canada) considers a nuchal fold to be abnormal when the measurement is ≥ 5 mm at 16-18 weeks, or ≥ to 6 mm at 18 to 24 weeks.
What is a good nuchal fold measurement?
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.
Can a thick nuchal fold go away?
Natural course. An abnormally thickened nuchal fold or even a cystic hygroma may resolve, especially toward the third trimester; however, the risk of karyotypic abnormalities is not reduced.
How accurate is the nuchal fold measurement?
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.
Can nuchal fold measurement be wrong?
The screening was wrongly inconspicuous in 12 cases and in 479 cases the FTS offered false-positive results. An assumed NT error of +/-0.1 mm already causes a highly significant change in the false-positive rate. A difference of -0.2 mm leads to a visible change in false negatives.
What is a high nuchal fold measurement?
About 90% of fetuses with a nuchal translucency measurement of 3 mm (“high”) at 12 weeks’ gestation are normal at birth, while 10% have major abnormalities. Only 10% of babies with a measurement of 6 mm (“very high”) at this time will be found to be normal.
When to expect a thick nuchal skin fold?
THICK NUCHAL FOLD. This nuchal skin fold increases with advancing gestational age and ranges between 1 and 5 mm in normal fetuses between 14 and 21 weeks gestation. A nuchal skin fold thickness of ³ 6 mm is considered abnormal between 14 and 21 weeks.
When to measure the nuchal fold in pregnancy?
Nuchal fold thickness of >6 mm is abnormal on a routine morphology ultrasound performed at 18-22 weeks. The nuchal fold is known to increase throughout the second trimester in a normal pregnancy, and may be measured during a broader window of 14 and 24 weeks when required.
What’s the optimal nuchal fold thickness for Down syndrome?
From 14 to 18 weeks’ gestation, a nuchal fold thickness of > or = 5 mm was the optimal threshold. Measurements of this magnitude were found in 2.9% of pregnancies and produced a sensitivity of 42% (11/26) for the detection of Down syndrome.
What do you need to know about the nuchal fold?
Nuchal fold 1 Terminology. It should not be confused with nuchal translucency, which is measured in the first trimester . 2 Epidemiology. The predominant reason for measuring the nuchal fold is that it is a soft marker for aneuploidy. 3 Pathology. 4 Radiographic features. 5 See also