While it is generally not expected that guests will bring presents to a brit milah ceremony, if this is the first time that you are visiting the parents of the newborn after the child’s birth and would otherwise bring a baby gift, attendance at a bris is a natural and convenient time to do so. There is even biblical justification for such gift-giving; after Abraham followed God’s commandment and had himself and the males in his community circumcised, God gave him and his progeny the land of Canaan in perpetuity.