Can you imagine discovering that the person you're engaged to is your half-sibling? Or that the city you grew up in is home to 149 more of your half siblings?
Parents of children conceived using donated sperm are becoming concerned about precisely these possibilities. And their concerns are rising due to the emergence of registry sites, where they can search to see if their child has donor half-siblings. The sites reveal the existence of large "donor families," including one case reported by the New York Times in which a sperm donor may have fathered at least 150 children.
Incest isn't the only issue setting off alarm bells; habitual donors can pass on disease-causing genes, which would then spread through the population as the donors' offspring have their own children.
Countries such as England, France, and Sweden have limits on the number of children from one sperm donor, but there's no such law the US.
Do you think sperm donation in the US should be subject to stricter regulations?