A Wisconsin woman and her son are suing a fertility doctor, alleging that he used his own sperm to father the son nearly 40 years ago, instead of the anonymous donor she believed was used. Mary Ellen Lukezich, 71, claims in a lawsuit filed August 6 that Dr. Frederick Dettmann, now 91, recommended artificial insemination in 1982 after other fertility treatments failed.
Dettmann allegedly told Lukezich that the donor would be an anonymous, healthy young medical student. The lawsuit states that Dettmann instead used his own sperm, leading to the birth of her son, Joseph Laedtke Heider, in 1983. Lukezich and Heider, 43, discovered the alleged deception after Heider submitted his DNA to Ancestry.com in December 2024.
According to the lawsuit, Heider's DNA results indicated multiple half-siblings and a direct genetic link to Dr. Dettmann's family, establishing the doctor as his biological father. Heider expressed feelings of betrayal upon learning his identity was based on a lie.
"What he did was incomprehensible and it was such a betrayal of trust that I just wanted to make sure that if I have the opportunity to hold him accountable for the pain that he caused my mom and the things he put her through, that maybe she didn't even know at the time," Heider said, as reported by WISN.
Lukezich told NBC News that she felt violated by the doctor's alleged actions. "I feel like I've been raped," she stated. "And it's not right. And I want other women to feel OK about coming forward with this."
The lawsuit names the Wisconsin Health Care Liability Insurance Plan and ABC Insurance Co. as defendants, along with Dettmann. Their attorney, Al Foeckler, stated at a press conference that families often approach fertility doctors in a state of hope and vulnerability, trusting them implicitly. "Dr Frederick Dettmann preyed on that desperation. He exploited that trust," Foeckler said.
Foeckler also mentioned that since the press conference, multiple women have contacted him with uncomfortable interactions with Dettmann dating back to the 1970s. He described the doctor as a "serial predator of women."
Dr. Dettmann, through his legal team, denied the allegations. "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 statement read, according to WISN.
Whitefish Bay police records indicate Dettmann was accused of assault during a gynecological exam in 1985, but no charges were filed due to the difficulty of proving the assault. Records also show the sexual assault complaint was reported to Wisconsin's medical licensing board, which closed the case in 1986. A spokesperson for the Wisconsin Department of Safety and Professional Services stated they do not have records of closed complaints from that era.
Dettmann retired in the 1990s and currently resides in Arizona. Heider reportedly has nine other alleged half-siblings fathered by the doctor.