A Dutch IVF Doctor Secretly Used His Sperm to Father 49 Kids

A collection of Jan Karbaat’s children (now adults) who were involved in the case. Photo: Getty Images

For decades, a Dutch fertility doctor secretly swapped in his own sperm for donor samples while administering IVF treatments: On Friday, DNA tests finally confirmed the late Jan Karbaat fathered dozens of his patients’ children without their knowledge or consent. After judges ordered the release of a sealed record detailing Karbaat’s genetic profile, a group of his suspected descendants underwent paternity tests, and according to The Guardian, 49 came back as direct matches.

Before he died in 2017, Karbaat admitted to begetting maybe 60 children during his time operating a fertility clinic. According to the New York Times, clinic may actually be a generous term: “Karbaat ran a sperm bank in the rear of his stately yellow brick house” in the town of Barendrecht, near Rotterdam. He helped patients conceive an estimated 10,000 babies between 1980 and 2009, when authorities shuttered the practice over concerns about its storage methods and various other infractions. According to the Times, record-keeping was shoddy enough to preclude the possibility of reliably verifying donors’ identities. Suspicions reportedly heightened when two of a patient’s children underwent paternity tests and discovered that they were half-siblings, rather than full-siblings. And then, there was the uncanny familial resemblance among children conceived at Karbaat’s clinic to contend with.

In 2017, a group of parents and so-called “Karbaat children” sued the doctor’s family a month after the 89-year-old died, according to The Guardian. At the time, a judge ruled that Karbaat’s DNA could be collected posthumously, from personal affects like his toothbrush, but that the profile would have to stay locked in a safe until another judge weighed in on what to do with it. In February, the Rotterdam District Court decided that enough evidence existed to credibly suggest Karbaat had been using his own genetic material to inseminate patients, and furthermore, that he may have covertly fathered as many as 200 kids, unbeknownst to their parents.

Armed with the doctor’s DNA, parents and possible children were permitted to undertake their own tests, the results of which confirmed “serious suspicions that Karbaat used his own sperm at his clinic,” the Defense for Children (a Switzerland-based children’s rights organization that aided in the lawsuit) said in a statement.

Apparently, though, not all Karbaat’s secret children felt burdened by their paternity. “I don’t get the feeling that he cheated my mother,” one Eric Lever reportedly told a Dutch daily. “She really wanted a child and could not have one with my paternal father.”

Others felt grateful to close the book. “After a search of 11 years I can continue my life,” a man named Joey said, according to the BBC. “I am glad that I finally have clarity.”

A Dutch IVF Doctor Secretly Used His Sperm to Father 49 Kids