Fertility doctor sued after woman and son claim his own sperm was used to impregnate her

A mother and son have accused a fertility doctor of using his own sperm for the conception without her consent.

In a complaint filed on 6 August in Milwaukee County Circuit by Mary Ellen Lukezich and her son, Joseph Laedtke Heider, allege the incident happened in the 1980s.

Lukezich, who was 25 at the time, and her husband, Thomas Laedtke, were trying to expand their family but struggled to conceive.

She decided to undergo artificial insemination with the help of her OB-GYN and fertility specialist, Dr Frederick Dettmann, with sperm from an anonymous donor believed to be a 'healthy young medical student', the suit states.

Lukezich found out that she was pregnant in 1982 and welcomed Joseph the next year.

However, over 40 years later, in 2024, Joseph discovered through a DNA test on Ancestry.com that Dr Dettmann was his biological father, according to the complaint.

Joseph Laedtke Heider was born in 1983 (TMJ4 News)

He said the results also showed he has a number of half-siblings as well as other family members whom he had no idea even existed.

“I got an email from Ancestry, which is the company that I ordered the DNA test from, that I had a half-sister,” Laedtke told NBC News. “And so when I went into my DNA results and the relationships, I had noticed that there was multiple half-siblings that it had suggested that I was related to.”

The family’s attorney, Al Foeckler, alleges Dr Dettmann never told Lukezich that he was using his own sperm for the insemination and did so without her consent.

Joseph and his mum are now seeking an unspecified amount in damages, which will be determined at trial.

“Words cannot fully express what it feels like to learn that your entire identity is built on a lie told by a doctor who took an oath to do no harm,” Joseph said in a statement, reported by PEOPLE. “But as difficult as this has been for me, I think most about my mother. She was a young woman who wanted nothing more than to become a mother.”

Foeckler also told NBC News that several women have since come forward to share their own alleged interactions with the doctor.

Laedtke and his mother discovered he has several half siblings (TMJ4 News)

Sean Gaynor, Dettmann’s attorney, disputed the allegations on behalf of his 91-year-old retired client.

“The events referenced are alleged to have occurred almost 50 years ago,” Gaynor said in a statement to NBC News. “Dr Dettmann has no independent recollection of the individuals making these allegations and is unaware of any evidence supporting the claims being asserted.”

Tyla has approached Gaynor for further comment.