How do i fix this sims 3 glitch?

I have played the sims 3 multiple times with out it glitch but now with all the children there are huge glitches. when the child is born the stay unseen and cant be interacted with, and then even with other families i am not playing as the have deformed bodies, as in they still have the small bodies of the toddler or child, and even teenager, like, where theyre head are set is the same, but most noticably for the children and toddlers the have deformed more adult like bodies, its reall hard to explain, but if any one know what i am talking about and knows how to fix it, with out having to reinstall the game, if possible please answer and let me know!