Frequency of Urination during pregnancy
The uterus is growing and begins to press on the woman's bladder, causing the need for her to urinate more frequently. Further, the increased volume of body fluids and the improved efficiency of the kidneys, help to rid the body more quickly of waste products. The pressure on your bladder is often relieved once the uterus rises into the abdominal cavity around the fourth month and doesn't return until the third trimester when the baby "drops" back down into the pelvis in the ninth month. By leaning forward when you urinate, you will ensure that you empty your bladder completely and reduce trips to the bathroom.
It is important to remember that if you notice pain, burning, pus or blood in your urine to see your health care provider right away. You might have a urinary tract infection that needs treatment.