Incidence of Down's syndrome and maternal age

Maternal Incidence of Maternal Incidence of Age Down syndrome Age Down syndrome --------------------------------------------------------- 20 1 in 2,000 35 1 in 350 21 1 in 1,700 36 1 in 300 22 1 in 1,500 37 1 in 250 23 1 in 1,400 38 1 in 200 24 1 in 1,300 39 1 in 150 25 1 in 1,200 40 1 in 100 26 1 in 1,100 41 1 in 80 27 1 in 1,050 42 1 in 70 28 1 in 1,000 43 1 in 50 29 1 in 950 44 1 in 40 30 1 in 900 45 1 in 30 31 1 in 800 46 1 in 25 32 1 in 720 47 1 in 20 33 1 in 600 48 1 in 15 34 1 in 450 49 1 in 10