This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Congenital Anomalies of the CNS, Subject name: Pediatrics
[{'content': 'What is the best preventive measure for neural tube defects? \nSelect and explain. \nA. Vitamin B12 supplementation to mother, B. Folate supplementation to mother, C. BCG vaccination at birth, D. USG in 2nd trimester', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Folate supplementation to mother Neural tube defectso NTDs account for most congenital anomalies in CNS. It results from failure of neural tube to close spontaneously between 3rd-4th week of in utero developmento NTDs have multiple etiological factors :-# Maternal diabetes# Maternal exposure to alcohol, radiation, valproate, carbamazepine# Zinc and folate deficiency# Trisomy 13 and 15# Maternal malnutrition is an important risk factor for development of NTD. There is decreased maternal folatelevels in NTD affected pregnancies. Periconceptional folic acid supplementation decreases the occurrence of NTDo NTDs allow excretion of fetal substances like alpha-fetoprotein and acetylcholinesteraseinto amniotic fluid, which are used as prenatal biochemical markers for diagnosis", 'role': 'assistant'}]