The hospital gave them to me, told me that with bub being so small, it would make it easier for her. I got lots of mixed reaction about using them. One dr told me its good, the next told me that bub use to much energy to get the milk out, one told me that it' down-right unnessesary and that I must get her off sucking on them. I tried, but by that time she was so used to them that she would not suck on me directly. I used them till I gave up when she was three months. I feel that they did not stimulate enough to keep my milk production up to par, so if I were you, I would first let her bf without shields and only use them when really, really nessesary like craked nipples - my opinion.
Good luck!!