Have you noticed the nipples in the bottom row are often promoted as most “breast-like?” Interestingly, these nipple shapes can promote what we call “straw” sucking, where baby’s mouth closes around the tip of the nipple and doesn’t promote a deep latch. When babies “straw” suck on a bottle nipple, you might see gaps in the corners of the mouth which can lead to leaking milk, gulping air, etc.
If you and baby are experiencing bottle refusal, breast refusal (after introducing a bottle), or bottle/nipple preference, it may be worth trying one of the bottles with a more ideal nipple shape. We want the nipples we use to allow baby to switch from bottle to breast or vice versa very easily (if you’re nursing).
The bottles pictured at the top have a gradual widening between the nipple tip and base that typically provides for better mouth placement and a deeper latch.
Note: If the nipple shapes that are “less ideal” are working for you and baby, no need to change!