Which one of the following biochemical parameters is the most sensitive to detect open spina bifida?

Detection of NTD most specific test: ACE (acetylcholinesterase) most sensitive test: AFP (alfa feto protein) Neural tube defects can be distinguished from other fetal defects (e.g. abdominal wall defects) by use of the acetylcholinesterase test performed on amniotic fluid obtained by amniocentesis Acetylcholinesterase elevated along with AFP then a neural tube defect is likely. The Acetylcholinesterase level elevation is specific for the NTD's and if it is not elevated in presence of an elevated AFP, then a defect other then neural tube defect is suggested.