It seems like this subject of babies/children at Mass comes up regularly. I will say that some parents could/should do a better job of taking their noisy one(s) out, especially during the sermon and Consecration.
But maybe another consideration could be added to what has been said: every one of us was a baby at one time, and doubtless were fussy and distracting at times, so, when you can't tune it out, just figure that you're getting a little of your own back and offer it up.