I've heard of women whose breasts do get smaller and sort of deflated after breastfeeding. But, this really shouldn't be a concern. Pregnancy itself changes your breasts, they won't be the same as they were before you got pregnant. They may be the same size, but they won't be the same shape and won't have the same perkiness. The reason for these changes is to facilitate breastfeeding, so you might as well give it a try.As far as the health benefits from breastfeeding go, new formulas aren't that different. Both my kids were formula babies and they are much healthier and smarter than many of the breastfed kids we know. I have one friend who exclusively breastfed her son for over a year and he is constantly sick. Her formula fed son is much healthier. In my opinion, neither one is necessarily better than the other. It makes sense to at least try to breastfeed because your milk will come in no matter what. But if, for whatever reason, it doesn't work out, you shouldn't feel bad about using formula.