A man and his mother have filed a lawsuit against her fertility doctor after discovering that the man used his own sperm to impregnate her instead of the anonymous medical student she had been promised.

Key Takeaways:

• In 1982, Mary Ellen Lukezich (then Laedtke) went to Dr. Frederick Dettmann for fertility help.

• Dettmann ultimately suggested that she use a sperm donor and said he could provide sperm from an anonymous medical student.

• Lukezich agreed and became pregnant. She gave birth to a son, Joseph Laedtke Heider.

• More than 40 years later, Heider took an at-home DNA test and discovered that Dettmann is his biological father.

• The mother and son have filed a lawsuit against Dettmann, who is now 91 years old.

The Details:

Mary Ellen Lukezich and her son, Joseph Laedtke Heider, are suing Wisconsin Dr. Frederick Dettmann, alleging that he lied when he told Lukezich in 1982 that he would use the sperm of an anonymous "healthy young medical student" to impregnate her. Instead, he used his own sperm. Dettmann is now 91 years old and retired. He has denied any wrongdoing.

Heider said he learned Dettmann was his biological father after he took a DNA test through Ancestry.com in 2024. He also learned he has multiple half-siblings.

"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 stated.

Family sues former OB-GYN, alleging he used his own sperm to impregnate patient

Heider explained how it felt to learn the truth:

"The anonymous medical student donor that my mother was promised as my biological father never existed. Instead, the DNA led back to one person. Dr. Frederick Dettmann, the very doctor my mom trusted to help her have a child. Words cannot fully express what it feels like to learn that your entire identity is built on a lie."

According to a statement from Dettmann's attorneys, "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 ask for a specific amount of damages, but for the court to determine what those damages should be at trial.

Other former patients of Dettemann, who suspect he may have used his own sperm to impregnate them without their knowledge, are being asked to come forward.

The Bottom Line:

Thanks to the rise in at-home DNA test kit usage, many individuals have learned of the true circumstances of their conception and have faced identity crises as a result.

A woman named Brianna learned her mother's fertility doctor had also used his own sperm. She said, "I went through an identity crisis. It’s ongoing. I’ve had to come to terms with the idea that someone committed this act against my mom. And that I’m a product of it.”

More of these stories will likely come out as more individuals take DNA tests and make similar life-changing discoveries.