1. Causes of urinary incontinence in pregnant women Pregnant women incontinence refers to the involuntary leakage of urine when pregnant women cough, sneeze, walk and other activities. The main reason is that after pregnancy, the bladder gradually increases in size and presses on the bladder, resulting in reduced bladder capacity and decreased muscle tone, thus affecting the bladder\’s ability. 2. How to prevent urinary incontinence during pregnancy. In order to prevent urinary incontinence during pregnancy, pregnant women need to take the following measures: 1. Strengthen pelvic floor muscle exercises: The pelvic floor muscles are the ones that support the bladder.