Final answer:
Supine hypotensive syndrome occurs from the reduction of cardiac output due to compression of the inferior vena cava when pregnant women lie on their back, which can impede blood return to the heart and lead to hypotension.
Step-by-step explanation:
Supine hypotensive syndrome is a condition commonly experienced by pregnant women when they lie on their backs. This position allows the gravid uterus to compress vessels, affecting circulation and cardiac output. The correct answer to the question “Supine hypotensive syndrome occurs from”, is (B) reduction of cardiac output due to compression of the inferior vena cava. Compression of the inferior vena cava by the enlarging uterus can reduce the return of blood to the heart, resulting in decreased cardiac output and potential hypotension.
Conditions like orthostatic hypotension are somewhat related but occur due to different mechanisms, such as low blood volume or autonomic failure. The underlying causes can include dehydration or certain medications that affect fluid balance, which are managed by adjusting the medication or increasing fluid and salt intake. Similarly, autonomic conditions like diabetes can lead to peripheral nerve damage, affecting the postganglionic sympathetic fibers. Properly managing blood glucose levels in diabetes can improve such conditions.