The post about the woman who knew her mother had an abortion made me think. I'm never ever telling ds that I had an abortion. It doesn't help anything and just causes pain. I did it for socially acceptable reasons. I did it long before I had him. But I don't think it's easily forgivable when you perceive the fetus as your sibling.
So other than abortion, should parents avoid telling anything else? Provided the skeletons in the closet are long overcome and don't effect their current lives.