There are many in these fora who will decry the merits of bringing a young child or infant aboard aircraft, especially in premium classes, so beware. Others are paying significant amounts of money for comfort, luxury, peace and quiet and expect a modicum of same.

If the kid is quiet, it's best for all (fellow pax and your own sanity). If the kid isn't quiet, your job is to stand up in the galley and hold the child the entire flight across the Pacific, if necessary...been there, done that, but in economy. Parents who let their children wail endlessly while they enjoy champaign and caviar are not parents.

Airlines will generally let you bring (and use) carseats onboard if you have purchased a seat for the baby and the seat does not block aisle access for passengers to exit in an emergency. In the Prestige seats blockage probably won't be an issue, but positioning of the carseat may be. Did you buy a seat for the baby?

Best things you can do is to feed the child and get it to sleep the entire flight. Having the kid, if awake, suck on a bottle or teat while ascending is a good idea as it'll help with the pressure equalization.

Have a safe and enjoyable flight!