CooperSurgical, a major medical supply company, is facing a wave of lawsuits from patients who claim one of its products destroyed embryos created with in vitro fertilization.

Fertility clinics around the world used the product, a nutrient-rich liquid that helps fertilized eggs develop into embryos. This week federal regulators made public that the company had recalled three lots of the liquid, which was used in the clinics in November and December. The number of patients affected is unclear, although experts estimate they are in the thousands.

On Thursday, a Virginia couple filed a lawsuit against the company, the eighth in two months by families across the United States. Collectively, the patients say they lost more than 100 embryos that had been bathed in the defective product, known as culture medium.

The plaintiffs claim that all three batches of media were missing a key nutrient, magnesium, a defect that prevented their embryos from developing and left them unusable.

The company declined to comment on the lawsuits.

The Food and Drug Administration published a withdrawal notice on Wednesday said that nearly 1,000 bottles of culture media were affected, about half of which were purchased from clinics in the United States. The document said the company had notified affected clinics on December 13, telling them that “performance issues may lead to poor embryo development” and instructing customers to stop using the product.

Each bottle contains enough liquid for several patients, although it is unclear how many bottles were opened before the December recall. If the clinics had used even half of the affected vials, up to 20,000 patients could have been affected, said Mitchel C. Schiewe, an embryologist and laboratory director at California Fertility Partners, who he said briefly used the failed media in November.

Fertility medicine is a relatively new field with limited oversight by federal regulators. With the increase in demand for IVF, CooperSurgical has raced to position itself as an industry leader. Over the past decade it has acquired five smaller fertility companies.

CooperSurgical generated $1.2 billion in revenue last year, of which 40 percent came from its fertility services and supplies. The company owns large sperm and egg banks and sells genetic testing to ensure embryos are healthy.

In a call with investors in January, the company’s CEO noted that the company had achieved 12 consecutive quarters of “double-digit growth” in its fertility business.

The eight lawsuits describe a similar pattern of events. The couples had struggled for years to conceive. Many learned that they had created healthy embryos around Thanksgiving, only to learn on Christmas that the embryos had suddenly stopped growing.

He first demand It involved a Los Angeles couple who claim 34 embryos were destroyed by the defective media. His lawyer, Tracey Cowan, said the case represented a recent trend in manufacturing problems, a result of the rapid growth and consolidation of companies that supply the fertility industry with everything from freezers and pipettes for embryonic media.

“Ten years ago, most of my cases were all clinical negligence,” said Ms. Cowan, a partner at law firm Clarkson who has brought five cases involving CooperSurgical liquid. “Only recently, in the last few years, have we started to see many more cases of product recalls.”

In the newest case, brought to you by law firm Lieff Cabraser Heimann and Bernstein, a Virginia couple described a decade of painful efforts to conceive before turning to in vitro fertilization last fall. After adopting their son six years ago, the couple, Kearsten and Zachary Walden, were delighted to discover last summer that Mr. Walden’s insurance plan had added fertility coverage.

They quickly made an appointment with a local fertility clinic and an initial round of treatment produced six fertilized eggs. The Waldens were optimistic, they said in an interview, until they received a phone call on Thanksgiving morning, notifying them that all the embryos had stopped growing.

“I blamed myself a lot for being older,” said Ms. Walden, 39, who works in marketing in Norfolk, Virginia.

She began researching how she could produce healthier eggs in her next round, the last one that would be covered by her husband’s insurance. In January, her clinic notified her that they had used defective CooperSurgical media on her embryos.

“It was a rollercoaster of emotions,” Mrs. Walden said. “It was, wait a minute, so it’s not our fault or fault. So it was, how does something like this happen?