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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
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Bart's hydrops fetalis is lethal because:
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The correct answer is  c. Hb Bart's cannot release oxygen to fetal tissues(Ref: Nelson's 20/e p 2349-2352, Ghai 8/e p 341)As Hb Bart's consists of 4y chains, which have very high oxygen affinity, it cannot release oxygen to fetal tissues.