Dutch Mass Donor Simon Admits Fathering at Least 199 Children Across Europe

Letter to recipient parents

A 43-year-old Dutch sperm donor identified as Simon has acknowledged in a letter to recipient parents that he has fathered at least 199 children. The admission follows an initial report by the Dutch investigative television program Nieuwsuur, which originally linked him to 121 children. In his correspondence, Simon provided a breakdown of births across Europe, noting that one woman is currently pregnant. He wrote that he has ceased all sperm donation activities and intends to seek professional guidance. In his letter, the donor offered an explanation for concealing the true scale of his biological offspring.

As a result, parents received an incomplete or distorted picture. I believed I was doing the right thing and helping people; the appreciation and seeing intense happiness were my only motivation in this. Now I know that I have failed you severely.

Geographic scale and donor methods

Simon, who comes from the Groningen region in the northern Netherlands, operated under multiple aliases including Jesse, Johan, Daan, Sam, and Maarten. Over an active period of more than 15 years, he provided sperm both to licensed fertility clinics and directly to prospective mothers via the internet. Stichting Donorkind, the Dutch foundation for donor-conceived children, stated that his clinic donations alone exceeded statutory limits. Recipient mothers reported that he repeatedly lied about the number of children he had fathered, sent sexually suggestive messages, and offered sperm through sexual intercourse. The letter details 172 children born in the Netherlands, 15 in Germany, 11 in Belgium, and one in another European country.

Belgian regulatory investigation

The cross-border revelations prompted immediate regulatory scrutiny in Belgium. The Federal Agency for Medicines and Health Products (FAGG/AFMPS) announced on 29 August 2026 that it is verifying whether the donor operated within Belgian fertility clinics or through informal arrangements. Agency officials noted that the available press reports point to potential fraud. Investigative journalist Judith Pennarts had previously noted on public broadcaster VRT that Simon claimed to have assisted multiple families in Belgium and Germany. Agency spokeswoman Ann Eeckhout confirmed the formal outreach to authorities in the Netherlands.

We were informed by the media. We are now requesting all official information from the Dutch authorities.

Institutional oversight and committee appointment

The disclosures have drawn scrutiny toward Dutch regulatory oversight. The Dutch Ministry of Health possessed information in August 2017 establishing that Simon was acting as a mass donor, but took no enforcement action at the time. Two years later, in 2019, Simon was appointed to a government committee responsible for evaluating the Dutch donor law. The current inquiry gained traction in March 2026 when two mothers approached Ties van der Meer, chairman of Stichting Donorkind. Stichting Donorkind is currently in contact with a broader group of affected mothers, who have not yet indicated whether they plan to pursue legal action against the donor.