If you were asked to think of the man who has fathered the most children in the world, who'd be your pick? Jim Bob Duggar? Or the anonymous man who fathered 150 children? Both good guesses, but it's more likely Bertold Wiesner, who is likely the father of some 600 children. How exactly did he come to be so prolific? It's simple, really: He ran a fertility clinic in London in the 1940s, and he used his own sperm to inseminate a huge number of his patients. Ohhh.
Bertold Wiesner ran the clinic with his wife Mary Barton, who may have had no idea that her husband was fathering tons of kids right under her nose. During their run at the clinic, they helped women conceive around 1,500 babies. They promised to give these women smart offspring by using "high IQ donors," and their customers were under the impression that they used sperm donations from "a small number of highly intelligent friends." That certainly sounds dubious in this day in age, but back then this kind of practice wasn't nearly as formalized—though the clinic was considered controversial in its time because the practice of artificial insemination was still taboo.
Scandal isn't totally new to the clinic, either. it was the subject of a previous dust-up eleven years ago, when it was revealed that sperm from Derek Richter, a neurochemist, had been used to father more than 100 children. But that now pales in comparison to Wiesner's contribution, was only discovered recently, after two men, Barry Stevens and David Gollancz, who'd been conceived at the clinic, began researching it and discovered what was going on. DNA tests have now been conducted on 18 of the people who were conceived there between 1943 and 1962, and it's clear that two-thirds of them were fathered by Mr. Wiesner. If you extrapolate this to the whole population of kids conceived at the clinic, it means Wiesner has somewhere around 600 children roaming the planet. Holy shit. That is going to make for one hell of a family reunion, should they all decide to meet up someday.
By the way, Mr. Gollancz reports that if these numbers are correct, "A conservative estimate is that he would have been making 20 donations a year." Yikes. The Telegraph explains why this practice is frowned upon:
The same sperm donor should not be used to create so many children because of the risk that two of the offspring will unwittingly meet and start a family of their own, which could cause serious genetic problems in their children.
Well, inbreeding, sure, but also because it's really creepy and unethical for a doctor to be impregnating his patients with his own swimmers, without the patients' expressed consent and knowledge.
As for why Wiesner was such an, umm, enthusiastic donor, Stevens and Gollancz speculate that the couple had difficulty procuring donations because the procedure was still so controversial. So in order for them to stay in business, he had to provide the seed money, so to speak. Barton, for her part, always maintained that she'd limited the number of donations made by each man. While it seems difficult to believe, Stevens says it's entirely likely that she had no idea her husband was fathering children left and right:
He was the one that found the donors so it's possible that he didn't tell his wife and she believed the donations were coming from a lot of different men.
Hmm. We'll never know for sure, though since Wiesner died in 1972 and Barton has also passed away. Though he may be remembered as a real creep, what Mr. Wiesner did was not illegal back in his day—not that anyone even knew what he was doing or would have ever been able to prove it since DNA tests didn't exist. It is illegal now in England, and sperm donors are only allowed to "provide samples for the creation of up to ten families." That's still a sizeable amount, but Wiesner seems likely to hold onto the childbearing record with his 600 some kids for the foreseeable future.
British man 'fathered 600 children' at own fertility clinic [Telegraph]
British sperm donor ‘fathered 600 children' [Sunday Times (Sub. Req'd)]