Down' Syndrome Screenings

Down syndrome is also known as trisomy 21. It is the most common identifiable cause of learning disorder. Average life expectancy is 50 years old. About 1 in 10 die before age of 10.

The risk of down's syndrome in directly related to maternal age

• 25 years 1 in 1500
  
• 30 years 1 in 900
• 35 years 1 in 400
• 40 years 1 in 100
• 45 years 1 in 30

Screening Test for Down's Syndrome: Combine test

• 11 to 13 weeks
• Ultrasound: Nuchal Translucency (NT)
  
• Blood test:
• - Pregnancy associated plasma protein A (PAPP-A)
• - B-HCG
  

Interpreting the combine screening test

• 90% sensitive (detects 90%)
• 5% false positive

Screening Test for Down's Syndrome: Integrated test

• NT at 10 to 13 weeks
  
• PAPPA 10 weeks
• Oestriol, HCG, AFP, inhibin A in 15 weeks (Quadruple test)

Interpretation:

• 85% Sensitive
• 1.2% False positive
  
• Results out only after 15 weeks

These are the 2 most common tests. Other include the Quadruple test, serum integrated test (PAPP-A 10 weeks and quadruple test 15 weeks).