This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Physiological changes during Pregnancy, Subject name: Gynaecology & Obstetrics
BMR changes by what % in pregnancy 
Select and explain. 
A. Rise by 25%, B. Fall by 25%, C. Rise by 50%, D. Fall by 50%
A: Rise by 25%
Answer: A: Rise by 25% 
Explanation: Ans. A. Rise by 25%* During pregnancy glomerular filtration rate increases, which causes increased renal clearance of iodine.* Maternal serum iodine levels fall due to increased renal loss and also due to transplacental shift to the fetus. These cause hyperplasia of the gland.