On various parenting forums, I quite frequently see threads from women who are "devastated" to learn their baby's sex at the anomaly scan (boys seem to be the main source of disappointment). In almost all of these threads, at least one person says, "Don't worry, once your baby is born, you'll love them so much that you wouldn't swap them for the world."
If this is true, surely gender disappointment can be skipped altogether simply by not asking to learn the sex at the scan in the first place? I'm not saying it'll work in every case: Anne Bolelyn is proof that gender disappointment existed long before scans. Similarly, I doubt the men who insist that their wives have abortions because their culture views girls as inferior would be capable of loving a daughter under any circumstances. But barring strict cultural beliefs or severe mental illness, surely most people won't be disappointed in the baby once it's actually here?