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
With regards to acute pyelonephritis in pregnancy all of the following are true except: 
Select and explain. 
A. Left kidney is involved in 50% of patients, B. Most common isolate is E. coli, C. More common in later 1/2 of pregnancy, D. Responds to amino glycosides
A: Left kidney is involved in 50% of patients
Answer: A: Left kidney is involved in 50% of patients 
Explanation: Pyelonephritis in Pregnancy:
Etiology:

Incidence in pregnancy is 1-3%
More common in primigravida and young females
Usually occurs in the second trimester after 16 weeks (>50%) but may occur in 1st and 3rd as well
Generally bilateral, if unilateral it is more common on right side (in more than half of the cases)
Most common organism responsible E. coli (70%), Klebsiella (10%).

Complications