Which of the following tests are helpful in diagnosing neural tube defect?

Ans. (a) Acetyl choline esterase in the amniotic fluidRef.: Nelson 18th ed. / ch. 592* Failure of closure of the neural tube allows excretion of fetal substances (I+- - fetoprotein , acetylcholinesterase) into the amniotic fluid, serving as biochemical markers for a neural tube defect. Prenatal screening of maternal serum for AFP in the 16th to 18th wk of gestation is an effective method for identifying pregnancies at risk for fetuses with neural tube defects in utero.