For over 10 years, the Essure birth control implant has provided an alternative to surgical sterilization.

But for some patients, the complications associated with Essure are severe enough to outweigh the benefits.

When the FDA first approved Essure in 2002, it was the first alternative to tubal ligation for women seeking permanent birth control. The device is an implant that consists of a small coil made of a nickel-titanium alloy and a fiber similar to polyester.

The implant is placed in the fallopian tube. The implant then stimulates an inflammatory response that over the course of about three months causes scar tissue to form, blocking sperm from reaching the ova.

Compared to other forms of birth control, Essure has some advantages. Placement of the implant takes just 10 minutes in a doctor’s office, with no incision and little anesthesia. Recovery is much quicker: most patients are back to normal activity within one to two days.

Since there is no incision, the procedure leaves no visible scar. And as a non-hormonal birth control, Essure avoids the complications associated with hormone therapy.

Since initially approving the device for sale via a fast-track approval process, the FDA had received more than 4,000 complaints of serious Essure complications. In some women, the Essure implant punctured their fallopian tube and caused trauma to other organs.

Other women have reported back pain, pelvic pain, pain with intercourse, or menstruation much heavier or prolonged than normal. Others have reported headaches, fatigue, joint pain, and weight fluctuations.

Multiple studies conducted since Essure entered the market have found that several women who had received an Essure implant suffered perforation of the fallopian tubes or migration of the implant to the wrong part of the body. Some women required surgical intervention, either to remove the implant or to perform traditional tubal ligation.

Some women say their Essure complications were far worse than they had expected. One woman reported experiencing severe pain and uncontrollable bleeding for two years. Her doctors found the Essure coils had broken and migrated to her uterus, and she required a hysterectomy to remove them.

The FDA’s original fast-track approval for Essure was conditioned on continuation of the initial safety trials for four more years. As those trials continued, many participants reported unusually heavy periods, pelvic pain, painful periods, and pain with intercourse.

The long-term results of those trials were published in April in the Journal of Minimally Invasive Gynecology. Dr. Aileen Gairpey, an assistant professor at Yale School of Medicine, noted that the results were missing data on 30 percent of the women who initially participated in the trials. “[T]he most common reason patients are lost like this is because they had a problem,” she said.

Originally marketed by Conceptus Inc., Essure is now a product of Bayer Pharmaceuticals. Bayer says that about 750,000 Essure implants have been administered to in at least 23 different countries worldwide.

However, the manufacturer will not say how many women in the United States have been implanted with Essure, making it difficult for experts to evaluate whether the risks of Essure complications are excessive. Bayer insists that the benefits of using Essure continue to outweigh the risks.