This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Antenatal Screening, Subject name: Gynaecology & Obstetrics
[{'content': "Alpha feto protein is decreased in: (Repeat) \nSelect and explain. \nA. Spina bifida, B. Down's syndrome, C. Dead fetus, D. Abdominal wall deficiency", 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans: B (Down's syndrome) Ref: Dutta Textbook of Obstetrics pg 106Explanation:MATERNAL SERUM AFPAFP is oncofetal protein w ith molecular weight 70000It is produced by yolk sac and fetal liverHighest level of AFP in fetal serum and amniotic fluid is seen around 13 weeks and thereafter decreasesMaternal serum AFP reaches a peak around 32 weeksMSAFP level is elevated in:Wrong gestational ageOpen NTDMultiple pregnancyRh isoimmunisationIUFDAnterior abdominal wall defectsRenal anomaliesMSAFP is low in:Down's syndromeGTD Test is done between 15 to 20 weeks", 'role': 'assistant'}]