I have heard the labor is shortened with each pregnancy, and as long as you have been able to delivery naturally with all your children, then it should be fine. I know there can be certain complications with C-sections, and the possibility of the incision site tearing the futher along you get. I would definitely start doing your kegel exercises. After 4 children those muscles have to be a little worn, and you will need them to help support you during labor, and it will help you return to normal faster after the delivery too. congratulations with your 4th child, I wish you the best.