中枢神经系统(CNS)畸形是指CNS 结构的先天发育异常,大多于出生时即被发现,少数出生后逐渐明显。CNS 畸形在自然流产中发病率为20/1000;占染色体异常中之40%;胚胎危险率29/10,000;出生时发病率为14～111/万/年(或1/75～150);占各种畸形中之5～20%;死亡率60/万。CNS 畸形是小儿死亡的重要原因,生后第一年死亡 Central nervous system (CNS) deformity refers to the congenital dysplasia of the CNS structure, most of which are found at birth, with a few becoming apparent after birth. The incidence of CNS deformity is 20/1000 in spontaneous abortion; 40% of chromosomal abnormalities; embryo risk is 29 / 10,000; the incidence at birth is 14-11 / 10 000 / year (or 1/75 to 150); 5 to 20% of all kinds of deformities; the death rate is 60 / million. CNS deformity is an important cause of death in children, died in the first year after birth