Millions of couples each year used fertility treatments to try to have a baby. But one woman in California says she's be stripped of the chance to have a child with her husband because the sperm he donated before he died is missing.

Sarah Robertson's husband suffered from a genetic disease, and she fears his sperm may have been given to another patient. Her high school sweetheart Aaron Robertson was taken too soon. Now this widow's dreams of family are shattered once again.

Aaron had an illness that worsened as he got older, a condition known as Marfan Syndrome.

"Marfan's is a genetic disorder and it affects the connective tissues in your body," said Sarah.

Left untreated, Marfan Syndrome can be a death sentence.

Nine years into their marriage Aaron has a massive stroke, brought on by complications from the disease. After days in the hospital, a comatose Aaron dies.

Sarah says she had an idea that, in a small way, could keep her husband's legacy alive.

"I that very morning heard a radio show about women who had stored their husbands' sperm and it reminded me of a conversation that Aaron and I had about that very thing," said Sarah.

When the time came for children, Sarah would test Aaron's sperm for Marfan's, and if it was clear, she'd use it to have their child.

Sarah pays for storing the six vials of Aaron's sperm. But two years later, a change.

"Suddenly one year I got a bill with a different name on it," said Sarah.

The lab where Aaron's sperm was stored was sold and moved to a facility called Reproductive Fertility Center headed by Dr. Peyman Saadat. When she's ready to get the in-vitro treatment, Sarah contacts Dr. Saadat to retrieve Aaron's sperm in November 2014.

Over the course of months, Sarah says, the clinic gives her the runaround, claiming it has no records for Sarah. Then a fire destroyed her records and Aaron's sperm. All but one of the six vials of sperm were lost.

The last straw, Sarah says, is one devastating email: "It saddens me to be yet again the bearer of unfortunate news. Unfortunately as she wiped away the snow built up from the actual tissue vial she realized that the tissue belongs to another patient with the same first name and very similar last name. I can only imagine how disappointing this will be for you."

Sarah suspects it's more than incompetence. Suddenly the horror of Aaron's illness comes back to haunt her.

"I think [the vials] were used," said Sarah. "And I think there are children or embryos out there and people don't know they have this gene that could be lethal."

Sarah never had Aaron's sperm tested for Marfan Syndrome. She now lives in fear wondering if a family has a human time-bomb ticking in their child.

Sarah hired attorney Andrew Vorzimer in her search for the truth. And he claims what he found gives reason for worry.

"We found that the facility received six vials of Aaron Robertson's tissue and sperm," said Vorzimer.

Sarah's lawsuit alleges Dr. Saadat may have used those six vials of Aaron's sperm in other patients. Vorzimer claims this isn't the first time Saadat has been accused of doing something like this.

"I think what we had here was a genetic Ponzi scheme in which he used genetic material belonging to some patients and gave them to others," said Vorzimer.

Sarah's lawsuit against Saadat also alleges negligence, fraud and intentional infliction of emotional distress.

But Sarah says the suit isn't about money.

"There's a baby out there possibly that could have a genetic disease and may not know it."

"And that's the one thing that saved Aaron's life, knowing that he had it, that he had Marfan," said Sarah.

"All we asked for is that they notify any potential victim that they were the recipient of Aaron Robertson's sperm, that they recommend that the child undergo Marfan Syndrome testing," said Vorzimer. "They have refused."

Saadat also refused a request from Crime Watch Daily for comment.

What happened to Aaron's sperm? Was it used to make someone else's baby?

We went to Dr. Saadat's location in Burbank, Calif. to get answers, but he refused to talk to us on camera. His lawyer followed up on our unscheduled interview with an email that included this statement:

"It is not that Dr. Saadat doesn't wish to comment. It is merely the fact that this matter is in active litigation and we have no intention of trying this case in the media."

"My determination and focus at this point is to bring that man to justice and let his patients know as much as I possibly can what has happened," said Sarah.