Hi, dear I have gone through your question. I can understand your concern. Pus cells in urine or Pyuria is a common symptom for various medical conditions. The most common reason for Pyuria is the existence of urinary tract infection. It s not clear that pregnancy increases your risk of cystitis but pregnancy greatly increases the risk of getting a kidney infection because the high levels of the hormone progesterone decrease the muscle tone of the ureters (the tubes between the kidneys and the bladder), causing them to dilate and slowing the flow of urine. My advice is to meet immediately an nefrologist in your area for the right treatement of this problem in the third trimester of pregnancy Hope I have answered your question. If you have any further questions I will be happy to help. Thank you for usin HCM. Wish you good health.