Milwaukee, Wisconsin — A decades-old fertility treatment has led to a shocking legal battle after a Wisconsin mother and her son discovered through DNA testing that the doctor who helped her conceive may have secretly used his own sperm instead of the anonymous donor she had agreed to use.
The lawsuit, filed in Milwaukee County Circuit Court on Aug. 6, alleges that the doctor never informed the woman of the substitution or obtained her consent.
Mother Believed She Was Using Anonymous Donor
According to the complaint, Mary Ellen Lukezich was 25 years old in 1980 when she and her husband, Thomas Laedtke, were trying to have another child but struggled to conceive.
Lukezich eventually agreed to undergo artificial insemination through her longtime OB-GYN and fertility specialist, Dr. Frederick Dettmann.
She understood that the procedure would use sperm from an anonymous donor, whom she believed was a medical student. Lukezich became pregnant in 1982 and gave birth to her son, Joseph Laedtke Heider, the following year.
For decades, the family reportedly had no reason to question the circumstances surrounding Joseph’s conception.
DNA Test Changed Everything Decades Later
The family’s understanding of Joseph’s biological history changed in 2024, when he took a DNA test through Ancestry.com. According to the lawsuit, the results identified Dettmann as Joseph’s biological father.
The test also reportedly connected Joseph with multiple half-siblings and other relatives he had never previously known about. The discovery prompted Joseph and his mother to investigate how the unexpected biological connection could have occurred.
Their attorney, Al Foeckler, alleges that Dettmann secretly used his own sperm during the fertility procedure without telling Lukezich or obtaining her consent.
Son Says Discovery Changed His Entire Identity
Joseph described the revelation as deeply traumatic in a public statement.
He said learning that his biological father was allegedly the doctor who performed his mother’s fertility treatment left him feeling as though his identity had been built on a lie.
He also emphasized the impact on his mother, describing her as a young woman who simply wanted to become a parent when she sought fertility treatment.
The mother and son are seeking an unspecified amount of damages, with the final amount to be determined through the legal process.
Family Believes There May Be Other Patients
Joseph and Lukezich say they decided to speak publicly because they believe other former patients of Dettmann may have experienced similar situations.
Joseph encouraged anyone who underwent fertility treatment with Dettmann and later discovered unexpected relatives through DNA testing to come forward.
Their attorney said several women have already contacted him, describing what they characterized as uncomfortable interactions with Dettmann.
Those accounts are now part of the broader concerns surrounding the allegations, although the lawsuit’s claims have not been proven in court.
Retired Doctor’s Attorney Disputes Allegations
Dettmann, now 91 and retired in Arizona, has disputed the allegations through his attorney, Sean Gaynor. In a statement, Gaynor emphasized that the events described in the lawsuit allegedly occurred nearly 50 years ago.
He said Dettmann has no independent recollection of the individuals making the allegations and is unaware of evidence supporting the claims being made against him.
The legal dispute is now moving through the Wisconsin court system, where evidence and testimony will determine what happened during the fertility treatment decades ago.
For Joseph and his mother, however, the case represents more than a dispute over medical treatment. It is an attempt to understand a family history that remained hidden for generations and determine whether the doctor they trusted violated that trust.
What do you think about this case? Should fertility patients have additional protections against undisclosed donor substitutions? Share your thoughts in the comments below.
