Bodies and minds need breaks or the work suffers, this has been proven and reproven to the point where we don't even need to post links to support it.
Carolyn HaxI realize that people fly with small children all the time, and that babies are easier in some ways because all they do is sit/lie around anyway, but damn it's hard to keep a baby comfortable on any flight, much less a long one, particularly amid the looks of horror they will get from fellow passengers as it dawns on them that their 10- to 13-hour flight might come with a soundtrack of screaming baby.
Carolyn Hax