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
The following changes occur in urinary system in pregnancy except: 
Select and explain. 
A. Increased GFR, B. Increased RBF, C. Hypertrophy of bladder musculature, D. Increased activity of ureters
D: Increased activity of ureters
Answer: D: Increased activity of ureters 
Explanation: As discussed previously, during pregnancy – Glomerular filtration rate and renal blood flow increases i.e. option a and b are correct. Amongst option c and d; option d i.e. increased activity of ureters cannot be correct as the main hormone during pregnancy is progesterone which leads to relaxation of the smooth muscles of ureter. Therefore activity of ureters
decreases and leads to urinary stasis.
Anatomical changes in renal system during pregnancy.

Both kidneys enlarge in pregnancy 1 cm.
Hydroureter and hydronephrosis occurs due to relaxant effect progesterone (These changes are M/c on right side).
Congestion of bladder leading to decreased bladder capacity.
To compensate bladder pressure increases and intraurethral pressure increases.