1. What is NT MoM?

NT MoM (Multiple of Median) is a standardized measurement used in prenatal screening to assess nuchal translucency thickness. It helps in evaluating the risk of chromosomal abnormalities such as Down syndrome.

2. How Does the Calculator Work?

The calculator uses the NT MoM formula:

Where:

• \( NT\;measurement \) — Measured nuchal translucency thickness (mm)
• \( Median\;NT \) — Population median NT value for gestational age (mm)
• \( SD \) — Standard deviation of NT measurements (mm)

Explanation: The formula standardizes the NT measurement by comparing it to the population median, adjusted for gestational age.

3. Importance of NT Measurement

Details: Nuchal translucency measurement is a crucial first-trimester screening test that helps identify fetuses at increased risk for chromosomal abnormalities and congenital heart defects.

4. Using the Calculator

Tips: Enter the measured NT value, the appropriate median NT value for the gestational age, and the standard deviation. All values must be in millimeters and greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What is a normal NT MoM value?
A: A normal NT MoM typically ranges between 0.5-2.0. Values above 2.0 may indicate increased risk for chromosomal abnormalities.

Q2: When should NT measurement be performed?
A: NT measurement is ideally performed between 11-14 weeks of gestation when the crown-rump length is 45-84 mm.

Q3: How is median NT determined?
A: Median NT values are established based on large population studies and vary with gestational age. Laboratories use specific median tables for accurate calculation.

Q4: What factors can affect NT measurement?
A: Technical factors (measurement technique), maternal factors (weight, ethnicity), and fetal factors (gestational age, position) can all influence NT measurements.

Q5: Is NT screening diagnostic?
A: No, NT screening is a risk assessment tool. Abnormal results should be followed up with diagnostic tests such as CVS or amniocentesis for confirmation.