just kiddin My girls just started laying 2 weeks ago and they seem a little uncomfortable but it passes fast and then they quickly go about their business as content as ever!
It seems with mine that the bigger the bird the less it hurts. My Red sex link's first egg was a big one and she is a smaller bird she squacks and carrys on when she lays , My RIR is a bigger bird and her first egg was small ... and no egg song or sqaucking at all with her first . She must have what my grandma called "mommy hips ".
Probably not, at least for a normal hen. They are adapted to it and the pelvis is flexible, as is the duct and vent. Everything spreads, so to speak, to allow the egg to pass. Its what they do, if you will.
For those birds which have physical deformities or such problems, then it may very well be.