Objective: To pick out Down's syndrome and abnormal fetus of inborn neural tube defect, and reduce the birth of con-genital defect fetus through biochemical indicator detection of pregnancy serum markers. 目的通过母血清标记物生化指标检测,达到检出唐氏综合征(DS)及先天性神经管缺陷(NTD)异常胎儿,减少先天性缺陷胎儿的出生。