My daughters a year now and has been at a 2 since 3 or 4 months and just never went up anything faster she just made a mess and I felt like I was drowning her...I was worried too and her Dr just said it's no biggie as long as like Rima said too they're not showing the signs of frustration. My girl just likes to drink her bottle leisurely I guess ha but I think you're just fine letting him stick with the flow most comfortable for him.
^pretty much what @Rima said. I think we were on flow 2+ by about 3 months. I didn't even realize there were different flows until then. 😂 I wondered why my kid was finishing some bottles fast and others taking forever. I think we hit flow 5 around 7 months. But yes basically use your judgement and what your baby is comfortable with.
Used them since birth too
My son is 3 months and has been using size 3 since a month old. It just took forever for him to finish a bottle on size 1 and 2.
I used these bottles with my son since birth, he is 6months now and I just upgraded him to the 4th flow (3months+). I think it’s totally fine for you to keep using flow 1 (it says 1month+ so the plus means you can keep using it). You can know when an upgrade is needed when you see the sings, if your baby is doing a lot of effort to feed or he is getting frustrated and bored mid bottle and stops eating everytime it means he is getting tired of sucking and it’s time to move to the next flow. You will know just trust your instinct