Down syndrome occurs in about one per 1000 babies born each year.
Down syndrome . The possibility increases from less than 0.1 % in 20-year-old mothers to 3 % in those age 45 . It occurs in about one per 1000 babies born each year . In 2015 , Down syndrome was present in 5.4 million individuals and resulted in 27,000 deaths down from 43,000 deaths in 1990 .