In between clothing/diaper sizes

I had this problem! For diapers, we had to get a different brand for size 1 until he fit into them. Pampers swaddlers and Kirkland both fit large! Pampers pure and Kudos both fit smaller. For clothes, I just put him into onesies that were a little too big and it didn’t take long for him to fill them out.

Size up and fold them down! I find a that a bit bigger fit does better to prevent leaks during naps and longer sleep stretches too.

Our dude fits 0-3m on his torso, but wears nb pants. As for diapers, I agree with different brands having different sizes, but I tend to want to size up sooner rather than later.

Adding to what I said, I also like to use bigger sizes for nighttime and car rides. I use what's left of the small size for the daytime when he gets changed more frequently. There's also clothes and a bath on hand in case the small diaper doesn't make the cut.

My baby is 9lbs and in 0-3 clothing and size 1 diapers. Initially the size 1 diapers were too big so I did end up folding the diapers down until she was able to fit into them. As previously stated, sizes vary with different diaper brands. I typically use Huggies or pampers but I’ve noticed Huggies run a little bigger than pampers do.

Different brands size differently, i found that Gerber and Honest company 0-3 fits my 10 lbs baby. Should fit your 12lbs baby too