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
All of the following changes are seen in pregnancy except: 
Select and explain. 
A. Increased stroke volume, B. Increased cardiac output, C. Increased Intravascular volume, D. Increased peripheral vascular resistance
D: Increased peripheral vascular resistance
Answer: D: Increased peripheral vascular resistance 
Explanation: Ans. is d, i.e. Increased peripheral vascular resistanceRef: Dutta Obs. 7/e, p 51-53As discussed in detail:Blood volume increases during pregnancyCardiac output = Stroke volume x Heart rateAll these three parameters increase during pregnancyIn pregnancy since the main hormone is progesterone, which has a smooth muscle relaxant effect so peripheral vascular resistance decreases during pregnancy (and not increases).