Just weight and height. If they are up to date on their 2,4.and 6 month shots then that should be about it. They'll of course listen to heart, lungs, etc. Ask you some questions on their development and that is about it.
My son went in for his 9-month check-up yesterday. All they did was ask about his development. He was already up-to-date with his shots and didn't need any more til his 1-year check up. It just depends on the vaccination plan you and the pediatric agreed on. Your girls might or might not need shots. It won't differ much from any other check-ups. :)