regression

I just recently had my fourth child. My now second to youngest child who is 3 yrs old has started regressing. I don't know how to handle it. He has started wetting his pants sucking a pacifier and using a bottle. He sometimes wants to be held like a baby also. Should we give in and just be patient or should we start taking things away that he likes when he wets his pants and keep away the pacifier and bottle.