Lawsuit: Former fertility doctor used own sperm to impregnate patient without her knowledge

Anchor/Investigative Reporter

MILWAUKEE —

A Wisconsin woman and her son sued a former Milwaukee-area fertility doctor, alleging he used his own sperm to impregnate her without her knowledge or consent in 1982.

WARNING: Some may find the details in the lawsuit to be disturbing.

Mary Ellen Lukezich and her son, Joseph Laedtke Heider, filed the lawsuit Aug. 6 in Milwaukee County Circuit Court.

The lawsuit said the mother and son made the discovery in 2024 after Heider submitted a DNA sample to Ancestry.com and learned he had multiple half-siblings linked to Dr. Frederick Dettmann.

“Upon tracing these DNA connections, Joseph identified a direct genetic link to Dr. Dettmann’s family; that upon information and belief, this genetic information established that Dr. Dettmann is Joseph’s biological father,” the lawsuit said.

Lukezich, who went by the last name Laedtke in 1982, was a patient of Dettmann’s seeking fertility treatment. After medication and surgical treatments were unsuccessful, Dettmann recommended artificial insemination, the lawsuit said.

The document said Dettmann told Laedtke the donor would be an anonymous, “healthy young medical school student” whose identity would remain confidential.

During a fertility procedure, the lawsuit claims, Dettmann inseminated Laedtke with his own sperm. The lawsuit said Lukezich gave birth to Joseph the following year.

She believed for more than 40 years that Joseph’s biological father was the anonymous medical student Dettmann had described, the lawsuit said.

“The anonymous medical student donor that my mother was promised as my biological father never existed. Instead, the DNA led back to one person. Doctor Frederick Dettmann, the very doctor my mom trusted to help her have a child,” Heider said at a news conference in June.

“Words cannot fully express what it feels like to learn that your entire identity is built on a lie,” he added.

“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. Doctor Frederick Dettmann preyed on that desperation. He exploited that trust,” attorney Al Foeckler said in June on behalf of the mother and son.

“Dr. Dettmann, currently age 91, is aware of the claims being suggested. Due to HIPAA and Wisconsin’s medical confidentiality laws, he cannot comment on any patient care he rendered during his career,” a statement from Dettmann’s legal team said.

“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 request a specific amount in damages; instead, it requests a court to determine that amount at trial.

The lawyers for the mother and son are asking any other former patients who believe they may be in the same situation to reach out.