Fertility Doctor Accused of Secretly Fathering Patient's Son With His Own Sperm in Bombshell Lawsuit
A fertility doctor has been accused of secretly fathering a patient's son with his sperm in a bombshell lawsuit.
Aug. 31 2026, Published 7:08 p.m. ET
In the ultimate betrayal, a 71-year-old woman was horrified to learn her fertility doctor secretly fathered her son, RadarOnline.com can reveal.
Mary Ellen Lukezick and her son Joseph Laedtke Heider, 37, have slapped her former OB-GYN, Dr. Frederick Dettmann, with a lawsuit.
Shocking DNA Test Exposes Massive Lie
Joseph Laedtke Heider discovered her mother's fertility doctor secretly fathered him.
The two filed the bombshell suit in a Wisconsin court after results from a DNA test in 2024 indicated Heider had a whopping nine half-siblings — and he was directly related to Dettmann.
"Words cannot fully express what it feels like to learn that your entire identity is built on a lie," said Heider.
According to the suit, Lukezick was a patient of Dettmann seeking fertility treatment in 1982. After medication and surgical treatments were unsuccessful, he recommended artificial insemination.
Doctor Secretly Used His Own Sperm
DNA test results revealed Heider shared genetic links with nine half-siblings.
Dettmann claimed the donor would be an anonymous, "healthy young medical school student" whose identity would remain confidential, the suit said.
During a fertility procedure, the lawsuit claims, Dettmann inseminated Lukezick with his own sperm and she gave birth to Joseph the following year.
Mother and son discovered in 2024 after Heider submitted a DNA sample to Ancestry.com and learned he had multiple half-siblings linked to Dettmann.
Victims Speak Out Against Betrayal
Attorney Al Foeckler labeled Dettmann a serial predator of vulnerable women.
Blasting Dettmann’s behavior as "incomprehensible" and "a betrayal of trust,' Heider said he filed the suit to "make sure I have the opportunity to hold him accountable for the pain that he caused my mom."
His mother says: "I feel like I’ve been raped. It’s not right — and I want other women to feel okay about coming forward with this."
Their attorney, Al Foeckler, said: "These families come to fertility doctors at their most hopeful and their most helpless time.
"Trusting completely in the physician who holds their dreams of parenthood in their hands, Dr. Frederick Dettmann preyed on that desperation. He exploited that trust."
Was This Doctor A Serial Predator?
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Police records showed a past 1985 assault allegation against Dettmann.
Multiple women have come forward to share they had uncomfortable experiences with Dr. Dettmann as far back as the 1970s, Foeckler said.
According to police records in Whitefish Bay, Wis., Dettmann was accused of assaulting a woman during a gynecological exam in 1985 but no charges were filed.
Foeckler said: "There is no question in my mind that this man was a serial predator of women."
Now retired, Dettmann has denied any wrongdoing.
The family’s suit, filed Aug. 6 in Milwaukee County Court, does not request a specific amount in damages. Instead, it requests a court to determine that amount at trial.
