These strangers all have the same biological father: the fertility doctor who helped their parents have a baby
In the documentary Seeds of Deceit, a group of ‘Karbaat children’ meet for the first time
"I'm your sister, apparently."
"I see the same mouths."
"I never thought I could have so many siblings."
A group of people gather at a restaurant in the Netherlands. Some have met before; some have chatted on WhatsApp or Facebook; but many are meeting for the very first time.
What's bringing them together? Shared DNA. They're all "Karbaat children."
Their biological father is Jan Karbaat, a Dutch fertility doctor and pioneer in the field of artificial insemination from the 1980s to the 2000s. Their mothers all visited Karbaat for help getting pregnant.
Karbaat would tell his patients that he'd used sperm from an anonymous donor or their partner, but that wasn't always the case. With dozens of women, Karbaat secretly used his own sperm.
'In some cases, it's almost shocking how much they look like you'
In 2019, DNA tests revealed that 49 people conceived using donor sperm matched with Karbaat. By 2020, at least 61 known offspring had matched with Karbaat, many of whom have connected via social media.
"At first, you don't know where to look," said Isabelle, one of Karbaat's children. "In some cases, it's almost shocking how much [the others] look like you. You don't know each other at all, and yet you have so much in common."
In the documentary Seeds of Deceit, some of Karbaat's biological children share their conflicted feelings about finding out their father isn't who they thought he was.
'My brother's brother is my brother's brother. Try getting your head around that'
Some Karbaat children and their parents were also surprised to discover that their siblings were actually half-siblings. In some cases, Karbaat used his own sperm for one child and another donor's sperm for a second child in the same family.
"My brother, Ivo, who I grew up with, is from another donor, although our parents were promised the same donor," Martjin said in the documentary.
"I am Dr. Karbaat's child," Joey said in the film. "My brother is from another donor, and my sister is my legal father's child. So we're all half-siblings."
"My little brother, who I grew up with, was DNA-matched last week with Joey's little brother," said Peter, who met Joey only recently. "So Joey and I are half-brothers; my brother and I are half-brothers; Dennis and Joey are half–brothers; but Mark and Dennis are also half-brothers."
"My brother's brother is my brother's brother," said Joey. "Try getting your head around that."
"There are three or four large clusters now of at least 40 donor children — it just goes on," Joey said. "And they are all mutually connected through a brother or a sister."
'Every month, there's a new match'
The total number of Karbaat children is unknown. "Eighty to 90 per cent of donor children don't know they are donor children," Ivo said in Seeds of Deceit.
"I keep the family tree up to date," said Martijn. "Every month, there's a new match with someone whose DNA test linked them to us."
In Seeds of Deceit, many of Karbaat's children share how they feel to be part of such a large group. There's a sense of belonging and recognition, but also disbelief, sadness, anger and questions about the traits they've inherited from their father.
"I'm scared I will cross the same moral boundaries that he crossed," said Inge. "Before I knew Karbaat was my father, I didn't worry about that so much."
Through the story of Jan Karbaat, Seeds of Deceit tackles the nature versus nurture debate, the desire to endure, and moral questions around anonymous sperm donation.
