Maternal Serum Screening
Down Syndrome, Trisomy 18 and Neural Tube Defects
Nuchal Translucency (NT)

March 2011
The nuchal translucency is a fluid-containing area behind the fetal neck as shown by the red arrow in the picture. The nuchal translucency measurement needs to be performed by experienced sonographers and should be obtained between 10 weeks and 13 weeks 6 days of gestation which is equivalent to a crown-rump length between 31 and 80 millimeters. The majority of fetuses with Down syndrome have an increase NT measurement when compared to normal fetuses of the same gestational age.
Nuchal Translucency (NT) |
Jump to section:
- Introduction
- What is Maternal Serum Screening?
- Who Should Be Offered Maternal Serum Screening?
- Maternal Serum Screening: Options
- Maternal Serum Screening: Risk Calculation
- First Trimester Serum Screening
- Nuchal Translucency (NT)
- Nuchal Translucency (NT)
- Nuchal Translucency (NT)
- First Trimester Serum Screening
- First Trimester Screening
- Second Trimester Screening
- Second Trimester Screening
- Second Trimester Screening
- Sequential Screening
- Sequential Screening
- Sequential Screening
- Sequential Screening
- Mayo Medical Laboratories Maternal Serum Screening Options
- References
- Questions?


