In pregnancy the tubes connecting the kidneys to the bladder become wider. This makes it easier for infected urine from the bladder in a pregnant woman with cystitis to splash up to the kidney and cause infection there. For this reason cystitis symptoms should be treated promptly when pregnant. If you have symptoms of cystitis such as burning or stinging when you pass urine, a fever and lower abdominal discomfort, see the doctor or nurse so that they can check the urine for infection. If suggestive of infection you will be offered antibiotics that are safe to take in pregnancy. Later on in pregnancy you may want to pass water more often, because the baby's head begins to press on your bladder as it makes its way into your pelvis.