Dutch man believed to have fathered more than 550 children

‘Obsessive’ sperm donor facing court action to force him to stop donating

An “obsessive” sperm donor who’s believed to have fathered more than 550 children in the Netherlands and around the world is to be challenged in a Dutch court to force him to stop donating – and to prevent him causing any further potential psychological harm to existing offspring.

Last year, Donorkind, the Dutch donor child foundation, which matches recipients with willing registered donors, revealed that at least 10 Dutch doctors had illegally used their own sperm over the years to impregnate women who believed they were being treated through official channels.

Although not a medic, “Jonathan M” (41) from The Hague has been many times more prolific than even the most nototious of the doctors – the most active of whom was Jan Karbaat, who died in 2017 after fathering 81 children at last count.

“Jonathan M has a global reach via the internet”, said Ties van der Meer, chair of the donor child foundation. “He does business with large international sperm banks. And officialdom has done nothing to stop him. That’s why we’re seeking an injunction through the courts.”


“M” first came to the attention of the national gynaecological association in 2017 when it emerged that he had fathered at least 102 children by donating to 10 different clinics across the Netherlands.

He also broke agreements with clinics and recipients to adhere to a limit of 25 babies, said Mark de Hek, lawyer for the foundation.

Those revelations led to him being placed on a gynaecological black list at home but he continued to operate abroad, particularly in Denmark and Ukraine, where he offered his services under the name “Ruud”. He’s now believed to live in Kenya.

Eva, a Dutch woman who had a child by “M” in 2018, and who has now joined the donor child foundation case against him, says: “If I had known he’d already fathered more than 100 children I’d never have chosen him.”

She says Donorkind wants the court to issue an injunction forcing “M” to stop donating. It wants to establish which clinics currently have his sperm in storage. And they want it destroyed, unless it’s reserved for a woman who has already had one of his children.

According to the foundation, donor children sometimes find it hard to cope with the knowledge that their fathers have dozens of other children, meaning they have dozens of half-brothers or half-sisters they may never meet. There’s also the possibility of incest or inbreeding.

“This is dangerous for the mental and physical health of the children”, said Mr de Hek.

The Netherlands is currently working on a central register of sperm donors, and has tightened the rules so that a single donor can donate to a maximum of 12 women rather than the current maximum of 25.

Peter Cluskey

Peter Cluskey

Peter Cluskey is a journalist and broadcaster based in The Hague, where he covers Dutch news and politics plus the work of organisations such as the International Criminal Court