I have a 2 1/2 month old who receives my breast milk in a bottle while I am at work. I am still using newborn nipples on the bottle. I know that with formula fed infants, you are supposed to adjust the size of the hole in the nipple as they get older. However, I have heard that with breastfed infants, you shouldn't advance the nipple because it will become too easy to drink from the bottle compared to the breast and may contribute to early weaning. Any other information or opinions?