I never read it or hear it on GB/Irish newspapers TV shows. To my ear it sounds shockingly dated. I think it's quite a nasty little word.
Both times I heard the word on US tv shows, it was used quite disparagingly. By Lynette Scavo (not MN LS!) to describe her husband's child prior to their marriage, and on Ugly Betty, to describe Daniel Meade's son who he knew nothing about.
In some ways the Americans are so careful with their choice of words. They call a babysitter a childcare provider.
But the scriptwriters obviously know what's acceptable in US society, and this is deemed OK. I am absolutely shocked. Even in holy catholic Ireland this would be perceived as being a nasty dig at children who can't control whether or not their parents were married or not.
OK. I'll try and calm down a bit now. Maybe I should watch fewer American TV shows and read a good book.