(2) Pregnant women who have been pregnant with a fetus with multiple genetic abnormalities and pregnant women who have been pregnant with anencephaly have a 5% to 10% risk of becoming pregnant again. (3) Women over 35 years old are more likely to give birth to newborns with chromosomal abnormalities as they age. At the age of 35, it is 1/365, at the age of 40, it is 1/109, and at the age of 45, it is 1/32. (4) Have a history of habitual miscarriage, stillbirth, or one spouse is pregnant