Couple Sues Florida Fertility Clinic for Alleged Sperm Mix-Up

A Florida couple is suing Brown Fertility clinic in Jacksonville, alleging that a mix-up in sperm used during in vitro fertilization (IVF) resulted in their daughter being conceived with the genetic material of a stranger, not the intended father.

Joshua and Natalie Strong filed a lawsuit in Duval County Circuit Court on Thursday, accusing the clinic, its Medical Director Dr. Samuel Brown, and 10 other defendants of betraying their trust and causing the devastating error. The couple claims their daughter's paternity test confirmed another man fathered her, despite using Joshua's retrieved sperm for the procedure.

"They trusted Brown Fertility, as well as its founder and owner, Samuel E. Brown, M.D., with the family they hoped to build. That trust was betrayed," the lawsuit states. "The Strongs are now raising a daughter whose paternity test confirms that another man, not Joshua, fathered her."

Joshua Strong had previously undergone a vasectomy and required a surgical sperm retrieval, producing four vials of sperm for the clinic. The couple paid "tens of thousands of dollars" to Brown Fertility, which was recognized as one of "America’s Best Fertility Clinics" in 2025, for its services. The agreement stipulated that the clinic would use Joshua's sperm to fertilize Natalie's eggs for embryo creation and subsequent transfer.

Natalie gave birth to their daughter in June 2025. However, shortly after birth, routine newborn blood typing yielded results that were biologically impossible given the parents' blood types. Natalie has O Negative blood, and Joshua has A Negative blood, yet their daughter's blood type was identified as B Positive. Further DNA testing later confirmed a 0% probability that Joshua was the biological father.

"It took away the euphoria of having a baby," Natalie told First Coast News. "It was my first child, I was in heaven. It was the best day of my life and then when that hit us, it took all the happiness away, which we should have had for a very long time."

According to the lawsuit, the couple has informed the clinic of the test results, but the clinic has allegedly refused to admit fault, account for Joshua's sperm, or take responsibility. The couple suspects this may not be an isolated incident, noting that their first attempt at IVF with the clinic in mid-2024 resulted in a miscarriage. They allege that the wrong sperm might have been used in that pregnancy as well.

The lawsuit further questions the whereabouts of Joshua's sperm, expressing concern that it could have been misplaced, discarded, or used to create embryos for another couple without their knowledge. "The Strongs do not know whether Joshua has biological children, fathered without his knowledge, being raised today by other Brown Fertility patients who have no idea," the suit says.

The Strongs are seeking damages exceeding $50,000 and a jury trial. The lawsuit outlines the profound emotional toll on both parents: "Natalie suffers the daily knowledge that her body was used, twice, to carry a stranger’s child. Joshua suffers the daily knowledge that the daughter he is raising bears no biological connection to him, the loss of the irreplaceable genetic future he believed he was building with his wife, and the unending question of what became of his cryopreserved sperm."