4.Five birth defects most commonly seen were arranged in following orders : deformity of external ear, polydactyly, congenital heart disease, extremities shortness, cheiloschisis and palatoschisis.

• 发生率最高的出生缺陷疾病前五名排序为 :外耳畸形、多指 (趾 )畸形、先天性心脏病、肢体短缩、唇裂并腭裂。