Clinical Characteristics of 18-Trisomy Syndrome Failed to Be Diagnosed After Prenatal Screening

Edwards syndrome, also named as 18-trisomy syndrome, is the common chromosomal abnormalities with an incidence of 1 in 3000~8000 in live births [1]. Due to an extra chromosome 18, the main clinical manifestations are multiple malformations and severe mental retardation, which caused only few children could survive the first year and very few cases could live longer [1,2]. According clinical researches, about 50% of babies with trisomy 18 could live longer than one week and about 5-10% of children beyond the first year [3]. So, it seriously affected the health of children. It is well known that the program of prenatal screening and diagnosis is the effective way to avoid the birth of trisomy 18 baby.