This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hydramnios and Oligo Hydramnios, Subject name: Gynaecology & Obstetrics
[{'content': 'Blood loss of fetal origin: \nSelect and explain. \nA. Placenta previa, B. Vasa previa, C. Abruption Placenta, D. Circumvallate placenta', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. (b) Vasa previaRef. Dutta's obstetrics Th ed./259VASA PREVIA* In a vilamentous insertion of cord, the leash of blood vessels may traverse through membranes overlying the internal OS, in front of the presenting part. This condition is called Vasa previa.* Rupture of the membranes involves the overlying vessels and leads to vaginal bleeding.* This vaginal bleeding is, thus, entirely from fetal blood and may result in fetal exsanguination and even death.", 'role': 'assistant'}]