Can a newborn baby who has just completed a month switch to eating two types of formula milk at the same time?

Patient's question:

No

Doctor's answer:

Okay, here is the translation following your instructions:
It can be changed... In the initial stage of switching formula, you must mix the two formulas. Whether switching between different brands, or from one stage to another (even if the brand is the same), this process is called transitioning to a new formula.