If you feel your baby is stifling to suck on a 0 teat then go up to one. I don’t think I used 0 teats for long maybe a few weeks because of the struggle.
@Amanda she’s finishing the bottle no problem and still spits up after(sometimes) do you think I should stay at 0? I’m worried if Up it she won’t take to the breast anymore?
My son's speech therapist said to stick with a premie nipple. He's 8 months old and still uses the same flow for the 2 bottles he gets a day on top of breastfeeding. As for the suckling make sure the tip isn't clogged, I found the smaller sizes get clogged easier. It's normal for babies to spit up a bit while their tummies adjust to milk. Both of my kids spat up until we introduced solids. Burping can help with the spit up though.
For ebf, never. I upped the nipple size once we stopped breastfeeding and switched to only bottles.