One sperm donor has fathered 150 kids, and the children have been able to contact each other through a web-based registry created by one of the siblings.
In fact, 150 sounds like a big number, but the group is still growing. As the number of children born through artificial insemination increases, outsize groups of donor siblings are starting to appear.
“It’s wild when we see them all together – they all look alike,” said Daily, 48, a social worker in the Washington area.
While Daily’s group is among the largest, many others comprising 50 or more half siblings are cropping up on websites and in chat groups, where sperm donors are tagged with unique identifying numbers.
However, the production of these large groups does not sit well with some. It is leading to calls that cash-hungry sperm banks are allowing too many children to be conceived from one man. One concern is that genes for rare diseases could be spread more widely through the population.
Some experts note the increased odds of accidental incest between half sisters and half brothers from a single sperm donor, who often live close to one another.
“My daughter knows her donor’s number for this very reason,” said the mother of a teenager conceived from a donation. She asked that her name be withheld to protect her daughter’s privacy.
Although other countries, including Britain, France and Sweden, limit how many children a sperm donor can father, there is no such limit in the United States.
There are only guidelines issued by the American Society for Reproductive Medicine, a professional group that recommends restricting conceptions by individual sperm donors to 25 births per population of 800,000.