The lack of folic acid in diet during pregnancies is a major contributor.... increasing the pregnant woman's intake of folic acid, greatly reduces the chance of having a down syndrome child...
My sister is a Special Ed Teacher and for a time, worked with down syndrome children, who she said were the cutest and sweetest children she had ever worked with....
Though it's NOT the Gynecologists/abortion clinics who recommend or cause an abortion for the mother with a down syndrome child, as the op proclaims, the mother and father decide what is best for themselves including what they believe is best for their child to be... every circumstance is wholly different with each case/ with each couple