先天愚型,又称Ｄｏｗｎ氏综合征、２１-三体儿、软白痴、伸样痴呆,是人类第一个描述的染色体疾病,也是最为常见的染色体疾病之一。在所有智能落后的疾病中占１０%～１５%之多,严重影响社会和家庭的整体素质及健康幸福。随着生活水平的逐步提高,人们对优生优育知识的逐步加深以 Down’s syndrome, also known as Down’s syndrome, 21-trisomy, idiot, dementia dendrite, is the first description of human chromosome disease, is one of the most common chromosomal diseases. It accounts for 10% to 15% of all ill-informed diseases and seriously affects the overall quality of the society and the family as well as health and happiness. With the gradual improvement of living standards, people gradually deepen the knowledge of prenatal and postnatal care to