Not saying it's right or anything but just thought I'd let you know that I've heard of a few places where they won't do a guess/determination of the sex of the child - haven't ever heard the "because of PND" excuse though - the excuse has usually ben "cause people get upset and agry toward the sonogrpaher if its not the sex they want" and others are worried about the consequences if they get it wrong.

Just thought I'd let you know its certainly not the first time I've heard of it