A Florida couple says a fertility clinic mistakenly used another man’s sperm during IVF, leaving the husband facing a “zero percent probability” of being the biological father of their baby girl.
Natalie and Joshua Strong endured years of injections, hormone treatments, medication and the pain of a failed IVF cycle before welcoming their long-awaited daughter in 2025.
Their happiness lasted less than a day. Routine blood work following the baby’s birth indicated that Joshua was not her biological father.
The couple alleges that Brown Fertility in Jacksonville used sperm from an unidentified man to create the embryo that became their daughter. The clinic has denied the accusation, according to CNN.
A subsequent DNA test confirmed the devastating discovery.
“I just don’t understand how one little mistake like that could affect our whole lives forever,” Natalie told CBS News.
Natalie and Joshua are suing Brown Fertility and its lead physician, Dr. Samuel Brown. They want to learn the identity of their daughter’s biological father, determine how the alleged error occurred and find out what happened to Joshua’s sperm.
The couple is also worried that the possible mix-up could involve more than the daughter they are raising.

Natalie and Joshua Strong started IVF treatment in 2023, facing a failed cycle before eventually conceiving the baby girl they had long hoped to have together

Natalie and Joshua are pictured with their daughter, born in 2025 after their second IVF cycle. They learned after her birth that Joshua was not her biological father
The Strongs still have three embryos in storage, but say they do not know whose sperm was used to create them.
Joshua is also haunted by the possibility that his sperm may have been mistakenly used in another patient’s IVF treatment.
“We have no idea if they still have it, if they’ve used it elsewhere,” Joshua told CNN. “If there are other potential children somewhere, we have no idea.”
The ordeal began in the aftermath of what should have been one of the couple’s happiest moments.
Natalie and Joshua began IVF in 2023, hoping to have a biological child together. Their first attempt, however, was unsuccessful.
Natalie underwent another round of injections, hormone treatments and medication before the next attempt succeeded.
“We finally got our beautiful baby girl, and it was the best day of my life,” she said.
After the birth, the couple were told their daughter had type B positive blood, according to their lawsuit.

The couple’s joy became shock when their daughter’s blood type raised questions about her paternity, followed by DNA testing that found a “zero percent probability” Joshua was her biological father

Natalie kisses her baby daughter, who she says she loves ‘more than anything in the world’ despite the devastating discovery surrounding her conception
The Strongs both have negative blood types and the filing alleges the result was incompatible with Joshua being the biological father.
Joshua said he immediately realized something was wrong.
‘Within a day they told us her blood type and I pretty much knew immediately that something was messed up at that point,’ he said.
For Natalie, who had only just given birth, the revelation transformed a moment of euphoria into one of dread.
‘I was worried, confused,’ she recalled. ‘I didn’t know how that would be possible with all the stuff we’ve been through for the last few years.’
She stressed that nothing about the discovery changed how she felt about her newborn daughter.
‘I was so happy I had her and I love her more than anything in the world,’ Natalie said. ‘But to hear that right after you have your baby is devastating.’
Joshua has also spoken of his overwhelming and conflicting emotions.
‘Obviously, I love her tremendously. And I’m so happy that we have her,’ he said.
But he described the situation as ‘a struggle’ involving emotions that are difficult even to put into words.
At a press conference, Joshua became visibly upset as he discussed the ordeal.
‘I think about it every day,’ he said. ‘It’s just overwhelming at times.’

Natalie holds her daughter during a happy family moment. The couple say the IVF bombshell has not changed their love for the little girl and ‘couldn’t imagine not having her in our lives’

Joshua bowed his head as an emotional Natalie wiped away tears while the couple publicly discussed the alleged IVF mix-up that they say has changed their lives forever
The Strongs say they eventually intend to explain what happened to their daughter when she is old enough to understand.
Natalie said they believe questions about genetics, medical history and her appearance could make keeping the circumstances of her conception from her unrealistic.
‘We do eventually want to tell her when she’s old enough to understand,’ she said, adding that she hopes her daughter knows ‘that her parents are enough for her.’
The couple says identifying the biological father is important primarily because their daughter deserves to know her genetic and medical history.
The couple’s attorney, Rob Marcereau, said the lawsuit came only after almost a year of attempts to obtain answers from Brown Fertility.
‘We’ve gotten nothing,’ Marcereau said noting how the litigation is intended to determine ‘what happened, whose sperm was used, what happened to Joshua’s sperm’ and how such an alleged error could have occurred.
Brown Fertility has denied the Strongs’ claim with a spokesperson saying the clinic would not comment further while the case is being litigated.
The Strongs’ case also means their plans to grow their family are on hold.
They still have three embryos at Brown Fertility, but their attorneys say arrangements are being made to move them.
‘We have no idea whose sperm was used on the remaining three embryos,’ Joshua said. ‘We don’t have any clue.’

Joshua and Natalie are pictured with their daughter as they demand to know whose sperm was used to create her – and what happened to the sample Joshua provided to the fertility clinic

The couple filed a negligence lawsuit against the fertility clinic and their doctor, Dr Samuel Brown, lastThursday, claiming the wrong sperm was used to create their embryos

The couple conceived through IVF at Brown Fertility, but learned shortly after birth that their daughter had a blood type that made it biologically impossible for both of them to be the parents
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‘I am getting older and I don’t know how much longer I can process, you know, go through the process of that again,’ Natalie added.
For now, she said, the couple is concentrating on the little girl they spent years desperately trying to have.
‘We’re really happy with our daughter we have now,’ Natalie said. ‘We love her to death and we couldn’t imagine not having her in our lives.’
‘I have an interest in finding out what our baby’s genetic history is for her health reasons,’ Natalie said. ‘But further than that, no.’
Marcereau claimed fertility mistakes are more common than many Americans realize and alleged that inadequate staffing, training and quality controls can contribute to errors at some clinics.
Another attorney for the couple described fertility medicine in the US as the ‘Wild, Wild West of medicine,’ arguing that the industry lacks the kind of overarching regulation seen in some other countries.
Natalie said the family’s goal goes beyond obtaining answers for themselves and wants to make sure another couple does not endure the same experience.
‘I just hope they do better for the next couples they take care of,’ she said. ‘We don’t want it to happen to another family. It’s devastating.’