The Food and Drug Administration also said it may reclassify the devices in a higher-risk category that would require manufacturers, such as Boston Scientific and a unit of Johnson & Johnson, to conduct clinical trials in people before receiving approval for sale.

The companies could not be immediately reached for comment.

The devices, made of synthetic or biological material, are commonly implanted in women to repair weakened or damaged tissue and provide support in cases of pelvic organ prolapse (POP). They are also used to help those with a severe overactive bladder known as stress urinary incontinence.

The FDA said it received more than 1,500 reports of complications related to the repairs with mesh from 2008 to 2010, including cases in which the mesh eroded into the vagina or caused bleeding and infection. The rate of problems was five times the rate reported from 2005 to 2007.

The FDA sent letters this week to 35 manufacturers of transvaginal surgical mesh, requesting three-year studies of several hundred women each to study side effects, as well as the women's overall quality of life.

In July, the agency warned that complications with the mesh were "not rare" and that transvaginal organ repair using mesh may put patients at greater risk than other surgeries and treatments.

The FDA also said it was concerned about scientific studies that show a lack of clinical benefit from surgical mesh, compared to non-mesh repair.

About 75,000 women received mesh repairs for pelvic organ prolapse in 2010 and about 200,000 women received transvaginal repairs for stress urinary incontinence.

The agency is asking for more studies from companies that sell the mesh for POP surgery. In the case of mesh used to correct an overactive bladder, the FDA is seeking further study of use of a so-called "mini-sling," when strips of material are used around the bladder neck and the urethra.

During their lifetime, 30 percent to 50 percent of women may experience POP, with two percent developing symptoms. The condition happens when tissue that holds the pelvic organs in place becomes weak or stretched and bulges into the vagina.

Surgery to support prolapsing organs can be done through the abdomen or the vagina, either with stitches or also with surgical mesh for reinforcement.

Surgical mesh has been used since the 1950s to repair abdominal hernias, but doctors only started using the mesh for POP and stress urinary incontinence in the 1990s, a procedure that has grown in popularity.

Companies that wanted to make the mesh specifically for POP or urinary incontinence could submit their application under a 510(k) accelerated review application that did not require them to do clinical trials in people, as long as they could show their implants were similar to devices already on the market.

But during a panel meeting in September, outside advisers to the FDA recommended that the agency reclassify the devices for POP to require companies to submit additional studies. The FDA said it is considering their advice.

Jeffrey Grand, a lawyer at Bernstein Liebhard in New York, is representing women who are suing companies that make the transvaginal mesh, with a case going to trial later this year.

"These things were basically put on the market without any significant safety testing," Grand said. "I'm hoping that all of this brings about some regulatory changes."

• A Permanent Economic Emergency