Fertility doctor faces lawsuit for fathering patient’s child with his own sperm

In Wisconsin, a woman named Mary Ellen Lukezich is taking legal action against her former fertility doctor, Dr. Frederick Dettmann, after discovering that he used his own sperm to conceive her child instead of the anonymous donor he had promised. This revelation came to light when her son, Joseph Laedtke Heider, submitted his DNA to Ancestry.com in December 2024, only to find out that Dettmann was his biological father. The lawsuit, filed on August 6, 2026, claims that Heider has nine other half-siblings fathered by Dettmann, raising serious ethical concerns about the practices of fertility doctors. Lukezich, who sought treatment from Dettmann in 1982, felt betrayed and violated upon learning the truth about her son's paternity. She expressed her feelings of violation, stating, 'I feel like I've been raped.' The lawsuit has drawn attention to the trust that families place in fertility doctors during vulnerable times, with attorney Al Foeckler highlighting the emotional toll on families when such trust is broken. Since the announcement of the lawsuit, multiple women have come forward with their own allegations against Dettmann, suggesting a pattern of misconduct dating back to the 1970s. Dettmann, now 91 years old, has denied any wrongdoing, claiming he has no recollection of the allegations and is unaware of any supporting evidence. However, his past includes a 1985 accusation of assault during a gynecological exam, which was reported to the medical licensing board but ultimately closed in 1986. The case raises significant questions about the ethical responsibilities of fertility specialists and the potential for abuse of power in such intimate medical settings.