No Silly Questions: Will My Child Have a Hundred Half Siblings?

September 12, 2022

Read this week’s No Silly Questions blog on half siblings and pregnancy reporting.

I heard a story about a donor-conceived person discovering they had a hundred half siblings. Is that going to happen to my child?

It seems like we hear new stories every day about donor-conceived people sending their DNA into direct-to-consumer DNA ancestry sites and discovering they are connected to many more people than they had expected to be. One really important thing to keep in mind is that the donor-conceived people coming of age today are the product of the sperm banking standards of practice several decades ago. Our practices have changed significantly over the nearly 40 years that we have been in operation, in part because of feedback from our clients and their donor-conceived children. We understand the importance of limiting the number of families created using specimens from one donor.  As a result, Fairfax and all reputable sperm banks have policies in place to limit the number of families that can be created using the same sperm donor.  In the United States, Fairfax Cryobank has a family unit limit of 25, meaning that distribution of a donor will stop when we know that 25 families have had children using that donor. 

Another step we take at Fairfax Cryobank to cap the size of half-sibling groups is to limit the number of vials each donor can produce.  Based on the substantial historical pregnancy and birth information available to us, we calculate the ratio of the number of vials of donor sperm it typically takes to achieve a pregnancy and we limit a donor’s production to that amount.

We also monitor the locations of reported births for each donor and limit the geographic distribution of a donor’s specimens in accordance with guidelines from the American Society for Reproductive Medicine (ASRM).

One thing that may have contributed in the past to large numbers of donor-conceived people born from one donor’s sperm is that sperm banks had no way to check whether a donor applicant had already donated with a different sperm bank.  Fairfax Cryobank has long advocated for a national registry of sperm donors to help guard against donors participating with more than one sperm bank.  For over a decade, Fairfax Cryobank has collaborated with the other major US sperm bank to build a database of our sperm donors that is queried when each donor applies to one of the banks.  Neither of the banks will accept a donor into their program if he has already donated with another bank.

While our wealth of historical birth information helps us limit the number of vials sold to keep donors under our family limit, we also rely on our clients to be diligent in reporting pregnancies and births to us so we have real-time data to use.  Please help us adhere to our limitations on donor birth policy by keeping us updated on your family-building journey!


To keep up with more No Silly Questions, follow the Fairfax Cryobank blog.

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