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

Ans. is c i.e. Amniotic fluid acetyl cholinesterase Spina Bifida, anencephaly and encephalocele are collectively included under neural tube defect. As I have already explained in answer 3, amniotic fluid cholinesterase level is elevated in most cases of neural tube defects and has got better diagnostic value than AFP. Extra Edge : Ultrasonographic signs indicating Spina bifida. Small biparietal diameter. Ventriculomegaly. Frontal bone scalloping (the so called lemon sign).deg Elongation and downward displacement of the cerebellum (the so called banana sign).deg Effacement or obliteration of the cisterna magna.