Flying with infants is usually fine.

A healthy infant can tolerate the cabin environment and a long flight. The biggest concern is the exposure to hundreds of people in a closed cabin, some of whom may be contagious. For this reason, some practitioners recommend waiting until your child is more than six weeks old. A second concern is the discomfort to the ears on the ascent and descent. To minimize this, have your baby suck on the breast or bottle during those times, which equalizes the pressure in the ears the same way a hard swallow does. A third consideraton is the destination. If you are travelling to a developing area, be careful of the water and make sure that all your child's routine immunizations are up to date.