Also......when I was ill in hospital with appendicitis (when I was preggers) I had an amnio to try to diagnose what was wrong with me. The amniotic fluid was free of infection but they sent the results off to be genetically tested. I agreed to get it done as I figure the more info the better. It came back with an abnormal result which was pretty shocking. Everything turned out ok, the abnormality turned out to be harmless but we had to talk to a genetisist about the baby's family tree. Of course that involved talking about our donor. So within a couple of weeks of him being born we had to disclose that he was donor conceived to a doctor. So I imagine it would be pretty difficult to avoid telling anyone through the whole lifetime of the child if it was decided to not disclose the donor history to the child.