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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.
user
A 28-year-old woman in the third trimester of pregnancy has experienced severe dizziness for several days and is admitted to the hospital. During physical examination her blood pressure is normal when standing or sitting. When the patient is supine, her blood pressure drops to 90/50 mm Hg. What is the most likely explanation for these findings?
assistant
The correct answer is  The inferior vena cava quite likely undergoes compression by the growing fetus when the mother is in the supine position. In this case the compression led to reduced blood flow through the heart, with a resultant drop in blood pressure. The other structures listed as answers are not likely to be compressed by the growing fetus.