Gynaecology & Obstetrics The presence of increased levels of the following enzyme in amniotic fluid is an indicator of open neural tube defect in the fetus: A Phosphatidyl Esterase B Acetylcholinesterase C Pseudocholinesterase D Butyrylcholinesterase 💡 Explanation The presence of increased levels of the following enzyme in amniotic fluid is an indicator of open neural tube defect in the fetus: ✓ Correct Answer: B. Acetylcholinesterase