All of the following are physiological changes which occur during pregnancy, EXCEPT:

During pregnancy the renal plasma flow is increased by 50- 75%. It reaches the maximum value by 16 weeks and is maintained until 34 weeks. During pregnancy: Kidney enlarges in length by 1cm. GFR is increased by 50%. Increase in GFR causes reduction in maternal plasma level of creatinine, BUN and uric acid. Ureter becomes atonic, there is elongation, kinking and outward displacement of the ureter. Urinary bladder: Becomes congested with hyperophy of the muscles and elastic tissues of the wall. Ref: Textbook of Obstetrics By D C Dutta, 6th edn, page 55-6