Accidental Siblings

I have previously written about the inbreeding of superheroes and their strange families, so this paper that came out last fall felt both familiar and profoundly weird. Entitled "Full-sibling embryos created by anonymous gamete donation in unrelated recipients," it discusses two women who used donor eggs from the same woman, and then coincidentally chose the same sperm donor. So these two women, who are unrelated, likely don't know each other, and who could be living at opposite side of country, received embryos for full siblings with the same parents:

Both patients underwent their respective donor-recipient cycles without complication and each conceived twin gestations several months apart from each other. On routine review of recently completed cycles in our database, it was noted by our lab director that these donor-recipient cycles used the exact same oocyte donor and the exact same sperm donor. Full-sibling embryos had been created and transfered to two different women. At the time that this realization occurred, patient #1 was at 23 weeks’ gestational age with an ongoing pregnancy and supernumerary frozen embryos. Patient #2 suffered a spontaneous miscarriage at 9 weeks’ gestational age, but has frozen embryos for a potential future cycle.

There is certainly some mathematics here, at least when it comes to the odds of this occurring (which is increasing as these techniques become more common), but the article concludes by discussing some of the possible ethical implications:

When considering disclosure, the risks and benefits to the donor, recipient, and offspring must be considered. The overwhelming majority of studies in the literature focus mainly on the emotional impact on the child and on the parent-child relationship and support disclosure to anonymous gamete–conceived children. The Ethics Committee of the American Society for Reproductive Medicine states that disclosure to the child of the fact of donor conception may be in the best interest of the child. The question of whether recipients of full-sibling embryos randomly created by anonymous oocyte and sperm donation should be informed of one another has not been addressed to the best of our knowledge, likely because the creation of anonymous full siblings has never before been reported. This unique situation has led our practice to consider further counseling for all patients using donor gametes regarding the remote creation of anonymous full siblings. Currently, a policy of disclosure has not been established at our institution.

• Thanks to Jacob Kramer and Yael Kramer for the pointer to this article.*

Top image: Nicole O'Neil Photography/Flickr/CC-licensed