Can my 4mo baby start using 6mo pigeon teats?

Only size up if baby is finishing her milk slower than usual or u see that she doesn't want to finish her milk often. If u increase the teat flow now, baby will choke more due to the fast teat. Treat the cough and phlegm separately with meds, see PD.

Be careful when using the bigger months teats as sometimes the flow can be too fast for baby

Dont size up when baby is coughing it might choke her as the flow might be too fast

if you upsize it will make her sucking and swallowing worse, it may be too fast for her

nope cause it will cause issues like choking and cough even more.