There are different reasons for urinary incontinence. It could be weak pelvic floor muscles or it could be physical issues with the urethra or it could be the position or tilt of the bladder. Thankfully, I had no leaking during my pregnancy, nor afterwards, but I didn't deliver vaginally either. And of course there are surgery options to fix severe UI after pregnancy, but you usually won't be offered that option unless you are through having children.
I guess for now, keep those pads handy! Poor thing. At least you're taking it all with a smile. <img src="i/expressions/face-icon-small-smile.gif" border="0">