The risk increases with maternal age, however most babies with down syndrome are born to Mums under 35 -because older Mums are more likely to have prenatal testing.
First trimester screening is available to Mums of all ages. Mums over the age of 37 can go straight to cvs/amnio because it is this age at which the chance of having a child with down syndrome is greater than the risk of miscarriage from amnio (1/200).

