This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
[{'content': 'Increase acetylcholinesterase in amniotic fluid indicates – \nSelect and explain. \nA. Open neural tube defects, B. Oesophageal atresia, C. Down syndrome, D. Edward syndrome', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Prenatal diagnosis of neural tube defect\n\nIn intra embryonic life, neural tube is open at both end and freely communicate with amniotic cavity.\nFailure of closure of neural tube results in persistant of this communication.\nThis allows excretion of following fetal substances into amniotic cavity -\n\n\nAlpha - fetoprotein\nAcetylcholinesterase\n\n\nThese serve as biochemical marmkers for NTDs for prenatal diagnosis.', 'role': 'assistant'}]