Thank you to Debbie Kennett for sharing this YouTube video – How anonymous is an anonymous sperm or egg donor – Joyce Harper: https://www.youtube.com/watch?v=fdh2nBoiRNU&feature=youtu.be (around 1:28 minutes long).
Simply put, since so many people have DNA tested in the last few years, promises of anonymity are a thing of the past when it comes to egg and sperm donations. A friend’s brother was promised in the 1970s and 1980s that his donations were completely anonymous. Fast forward to a few years ago, my friend DNA tested at several companies and came up with a niece match, originally listed as 1st cousin match. Turns out, the niece is a result of his brother’s donation. Note: the brother who donated has not DNA tested although another brother later tested.
While one or both future parents and the donors may have signed confidentiality agreements, the child(ren) resulting from the donations did not. As I mentioned above, you don’t need for the donor to test as a close family member testing can easily reveal enough information to narrow down the donor to one of several families, and when close enough to one of the siblings.