Netherlands: 400 donor-conceived people have more than 25 half siblings

An internal investigation into the record-keeping of the now-closed donor sperm bank at Leiden University Medical Centre (LUMC) revealed that over 400 donor-conceived people have more than 25 half-siblings, confirming earlier allegations of the bank's administrative failures.

The donor sperm bank, operational between 1977 and 2004, had previously faced criticism for its disorganised administration after it was found many donor identities were untraceable. A recent analysis of the bank's archives, prompted by donor-conceived children seeking information about their biological father, confirmed the extent of the irregularities.

A total of 1173 children were conceived using sperm from the bank's 115 donors, with 754 women receiving treatment. To date, only a quarter of those affected have responded to the hospital's appeal to come forward. 'The results of the research so far show that of the 1173 descendants, 440 descendants have more than 25 half-brothers/sisters. But it has also become clear that there is a lot we do not yet know or cannot find out. For example, it is not possible to determine from which donor the donor sperm was used for 102 descendants,' said an LUMC spokesperson.

Dutch regulations introduced in 1992 limit sperm donors to fathering a maximum of 25 children, distributed among 12 women, to reduce the risk of incest and inbreeding. However, LUMC's investigation found that nine donors exceeded this limit, with one donor fathering nearly 90 children.

'The people involved feel cheated,' said Professor Martin Schalij, a member of LUMC's board of directors. 'We [LUMC] take our responsibility seriously by being open as far as possible and thus providing as much clarity as possible to all those involved. The report also showed that there were clues before 2023 indicating that the administration was incomplete. We realise that with the knowledge we have now, we should have reacted to these clues to inform the people involved. We deeply regret that we did not do this.'

LUMC is also investigating allegations that staff at the sperm bank may have used their own sperm during fertility treatments without informing patients. These claims surfaced last week after a known donor alerted the hospital to a 1980s article in the university magazine Mare, which mentioned staff members donating sperm for procedures. 'We are deeply shocked by this new information. We realise how impactful this is for all involved,' commented Professor Schalij.

The LUMC case is not an isolated incident. Similar scandals have emerged in other clinics where fertility specialists substituted their own sperm without patient consent or failed to maintain proper records. In January 2024, a laboratory technician at another clinic in Leiden was found to have fathered at least 11 children by using his sperm without registering as a donor (see BioNews 1224). Amid growing concerns, LUMC has called for a national investigation into the administration of sperm donor banks across the country.