Tracking Down Donor SiblingsEvery year thousands of children worldwide are born to mothers who have been artificially inseminated with sperm from an anonymous donor. The exact numbers are unknown since the industry is unregulated, but the numbers are estimated at anywhere from 30,000 to more than 100,000. Popular donors may have fathered more than a dozen children - creating quite an extended family tree! Although not as common, there are also several thousand children each year conceived through egg donation.
Donor offspring often have the same curiosity as any other individual about their genetic origins but, similar to adopted individuals, privacy laws protect the donor's identity. Sperm banks and egg donation facilities do provide non-identifying information about their donors, however, including donor number, physical appearance, medical history and other information. The Donor Sibling Registry, a Web site founded by Wendy Kramer and her 15-year-old donor-conceived son, lets you plug in your sperm bank or donor facility and the donor number to search for potential matches. It offers this service for both sperm donors and egg donors and has facilitated matches between more than 2000 half-siblings and/or donors.
Similar donor matching services are sometimes offered by specific donor facilities and sperm banks.
Tracking Down Anonymous Sperm DonorsWhile sperm banks will not go against a donor's privacy wishes and reveal the name of an anonymous sperm donor, DNA testing and online genealogical databases have made it possible to get around the privacy guarantees. A swab of saliva sent into a DNA testing lab provides a genetic profile that can then be compared against a database of genetic markers from other individuals. These DNA profiles are also generally private, but most people who participate in these services have asked to be informed when a close match occurs.
The Y-line DNA test discussed here analyzes the Y-chromosome passed down from father to son. For this reason, this research method will not work for female children of anonymous sperm donors unless you can locate a male donor sibling from the same donor.
Even if the anonymous donor has contributed their DNA to such a genealogy testing service, the research doesn't stop there. DNA genealogy testing isn't precise - it only guarantees that two individuals with a match share an ancestor in common. Depending upon the number of markers tested and the exactness of the match, this ancestor could be as recent as a father or grandfather, or ten or more generations back in the family tree.
If you're lucky enough to find a close match or two in a DNA database, then sharing details with these men may provide clues that traditional genealogy research can take further. Often you'll find these men share a similar surname, which may suggest the surname of the anonymous sperm donor. From there, you can use a people search service such as Omnitrace.com to compare the surname with details of the biological father provided by the sperm bank - such as his date or place of birth, education and medical history.
Kimberly Powell, About.com's Genealogy Guide since 2000, is a professional genealogist and the author of "Everything Family Tree, 2nd Edition." Click here for more information on Kimberly Powell.