A lobby group for Australian donor-conceived children has called for a national database to track donors to prevent accidental incest.

More and more women are resorting to unregulated donors whom they have discovered on the internet. Even formal donors are recorded in different databases, leading to confusion. And informal donors are not recorded at all.

According to The Guardian, “That raises concerns about ‘prolific donors’ having more families than are allowed under the current caps (which are five or 10 families in most states). It can also be traumatic for donor-conceived people to find out they have dozens of half siblings, and also raises the risk of accidental incest.”

Donor Conceived Australia says that people could find that they have half-siblings in several states, because sperm might have been shared amongst fertility clinics. “When donor-conceived people find out they have that many siblings, it is very distressing. We are now advising our members that you will never really know when you get to the full number,” she told The Guardian.

The head of DCA, Aimee Shackleton, says that Australia needs a central registry drawing together formal and informal donations.

However, one expert in reproductive health law points out that informal sperm donation had expanded a lot in recent years, thanks to the internet. Women are even using overseas donors. Many of these men might not want to appear on a register.