Down’s Syndrome – Epidemiology & Genetics

Risk of Down’s with Increasing Age

Age (years)                                   Risk

  • 20yrs                                             1 in 1,5000
  • 30yrs                                             1 in 800
  • 35yrs                                             1 in 270
  • 40yrs                                             1 in 100
  • 45yrs                                             1 in 50 or greater

(way to remember this: start at 1/1,000 at 30years then divide the denominator by 3 – i.e. 3 times more common) for every 5years.