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: Gynaecology & Obstetrics
[{'content': "In a pregnant woman of 28 weeks gestation IUD is earliest demonstrated on X-ray by : \nSelect and explain. \nA. Increased flexion, B. Overlapping of cranial bone, C. Spalding's sign, D. Gas in vessels", 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. is d i.e. Gas in vessels Robes sign i.e. presence of gas shadow in the chambers of the hea and great vessels. It is the earliest sign seen after IUD (12 hours after fetal death). Spalding sign i.e. overlapping of skull bones appears 7 days after death. Hyperflexion of the spine occurs in IUD and is more common. Sometimes hyperextension of neck may also be seen but they are late features.', 'role': 'assistant'}]