A Wisconsin family is suing a 91-year-old former gynecologist after a DNA test revealed he secretly used his own sperm to impregnate a patient who thought she was getting an anonymous donor — exposing yet another case where the medical establishment's self-policing failed a vulnerable patient entirely.
Mary Ellen Lukezich sought fertility treatment from Dr. Frederick Dettmann in Milwaukee in the early 1980s. When initial treatments failed, Dettmann suggested artificial insemination, telling Lukezich the donor would be an anonymous, healthy young medical school student who matched her and her late husband Thomas Laedtke's appearance, according to NBC News. She agreed. She was young, desperate to become a mother, and trusted her doctor. "I did whatever he asked me to do," Lukezich told NBC.
Four decades later, her son Joseph Laedtke Heider took a curiosity DNA test through Ancestry.com in December 2024. The results showed he had multiple half-siblings — the New York Post reports at least nine — all genetically linked to Dettmann. Heider only learned he'd been conceived via donor sperm when he called his mother with the results. She screamed when she realized Dettmann was the biological father.
"I feel like I've been raped," Lukezich said. "And it's not right. And I want other women to feel OK about coming forward with this."
Heider described the revelation as incomprehensible. "It was such a betrayal of trust that I just want to make sure that if I have the opportunity to hold him accountable for the pain that he caused my mom and the things that he put her through that maybe she didn't even know at the time," he told NBC.
The family filed suit on Aug. 6 and plans an additional civil battery claim, according to the Daily Caller. Their attorney, Allan Foeckler, says other women have contacted him about problematic interactions with Dettmann dating back to the 1970s. "There is no question in my mind that this man was a serial predator of women," Foeckler told NBC.
This wasn't Dettmann's first brush with an allegation. In 1985, a patient's husband filed a police report accusing Dettmann of assaulting his wife during a gynecological exam. Dettmann denied it. No charges were brought — authorities claimed it was too difficult to prove. Whitefish Bay Police Chief Patrick Whitaker now says the department has no open investigation and that records from the 1985 complaint would have been destroyed under retention laws.
So the system closed ranks then, and the records conveniently vanished now.
Dettmann, who retired in the 1990s and lives in Arizona, has attorney Sean Gaynor doing the predictable work: "The events referenced are alleged to have occurred almost 50 years ago. Dr. Dettmann has no independent recollection of the individuals making these allegations and is unaware of any evidence supporting the claims being asserted."
The lawsuit does not specify damages, instead asking a court to determine the amount at trial.
The question that hangs over this case is the same one that hangs over every fertility fraud scandal that commercial DNA testing has now exposed: how many more doctors did this, and how long did the institutions that were supposed to oversee them look the other way?
