One of the biggest things I see when it comes to bottle preference is simply using too large of a bottle nipple. In general, a mother's nipple size isn't gong to change - so neither should the bottle! You should always use the smallest nipple size that your child can tolerate. I know plenty of parents who have their child using a preemie nipple throughout the first year. I haven't seen very many situations where a child *needs* to be on a size 2 or 3 nipple - it's more often for the convenience of the person giving the bottle.