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: Anaesthesia
In a pregnant female, there is decreased requirement of the spinal anaesthetic agent because of all of the following except – 
Select and explain. 
A. Exaggerated lumbar lordosis, B. Decreased volume of subarachnoid space, C. Engorgement of epidural veins, D. Increased sensitivity of the nerves to anaesthetic agent
A: Exaggerated lumbar lordosis
Answer: A: Exaggerated lumbar lordosis 
Explanation: A smaller dose of local anaesthetic is nedded to produce the same level of neuraxial block in pregnant women compared with nonpregnant women.
The causes may be :-


Compression of the inferior vena cava by the pregnant uterus causes "distension or engorgment" of the epidural venous plexus. This decreases the volume of the epidural space and also the volume of the CSF per spinal segment. Therefore a given dose of epidural or intrathecal local anaesthetic will produce a greater degree of demiatomal involvement.
Pregnant women exhibit increase susceptibility to local anaesthetics.


Apex of lumbar lordosis cauded to thoracic kyphosis is reduced in supine position. This may enhance the cephalad spread of CSF.