Causes of Down syndrome Each person has 46 chromosomes arranged in 23 pairs. Because the male sperm and the female egg each have 23 chromosomes, when the sperm fertilizes the egg and conceives it, a new life is formed with all 46 chromosomes. However, sometimes errors can occur and cause chromosomal abnormalities. Down syndrome is one of these abnormalities. Down syndrome is caused by a chromosomal abnormality (an extra chromosome 21). How to prevent Down’s syndrome early 1, to avoid radiation away from electricity, avoid contact with chemical substances: in life to avoid radiation away from electricity, try not to carry out X-ray examination, away from substances with radiation, that is, do not watch television for too long; living in rural women of childbearing age should do a good job of protection against various pesticides and some chemical substances, to avoid direct contact. 2, avoid viral infection: viral infection is one of the causes of chromosome breakage, in the mumps, water beans, measles and other seasons, pregnant women should avoid contact with these affected children, and can use light salt water daily gargle, which can play the role of disinfection and disease prevention. 3, avoid a large number of drugs: during pregnancy pregnant women should try to avoid a large number of drugs, because many drugs can lead to the production of congenital infantile children. 4, choose the right age to plan pregnancy, try to avoid high age. 5.Maintain good living habits: Before preparing for pregnancy both men and women had better not smoke and drink alcohol, or smoke less and drink less, and maintain a good working environment and living environment. Pay attention to personal hygiene: pregnant women should take a bath at least once a week and rinse their perineum every day to maintain good personal hygiene habits, while preventing humidity in the living environment, keeping it dry and paying attention to ventilation. Pay attention to the appropriate amount of physical exercise: appropriate physical exercise to enhance the resistance of the body. 6, timely understanding of pregnancy status: for pregnant women with habitual miscarriage, they should not just carry out birth control, but timely understanding of pregnancy status, and if the diagnosis is confirmed as affected, they should consider whether to abort.