What does "Tangshi'er" mean?

　　Under normal circumstances, Down syndrome children usually refer to children suffering from Down syndrome. Detailed analysis is as follows:

　　Children with Down syndrome have an extra chromosome 21 in their bodies, which leads to abnormalities in physical and intellectual development. They usually experience significant intellectual disabilities, poor learning ability, and limited self-care skills. They also often have distinctive facial features such as wide-set eyes, flat nasal bridge, and protruding tongue. Some may also suffer from various health problems including congenital heart disease and gastrointestinal malformations. The birth of a child with Down syndrome can place a significant burden on families and society, so it is crucial to undergo appropriate screening and diagnosis during pregnancy.

　　Down syndrome screening is an important method for assessing the risk of fetal Down syndrome. It mainly includes early Down syndrome screening and mid-pregnancy screening, which calculates the risk of having a baby with Down syndrome by measuring the concentrations of specific substances in the blood and combining this data with the mother's age, weight, gestational age, and other factors. Currently, there is no cure for Down syndrome, but early intervention and special education can help improve the child's self-care and social skills, thereby enhancing their quality of life.