But in 2011, the FDA removed that contraindication and stated in an email, "there was no evidence from laboratory (bench) testing data, literature, market history information, and clinical trials to support a contraindication for nickel sensitivity."

The FDA spokesperson also wrote that the sensitivity to the device was found to be less than one percent.

After the FDA removed the nickel contraindication, the maker of Essure said it would be aggressively marketing that change to doctors.

Conceptus, Inc.,  the maker of Essure in 2011, boasted about the change in a press release and claimed they would be informing the OB/GYN community about the new expanded amount of women who would be able to have the procedure.

Despite the change in the contraindication material, nickel allergy information still appears on the website for Essure and the IFU material.

In the last line of the warnings section it states, "Patients who are allergic to nickel may have an allergic reaction to this device, especially those with a history of metal allergies."

Dr. McCarus said he informs his patients about the potential nickel allergy before performing the procedure, and so far he has not had any patients who he implanted with the device experience problems.

However, Dr. McCarus said he has had to perform several hysterectomies on other doctor’s patients for reasons other than a nickel allergy.

"The insert was either improperly placed and can perforate through the uterus, or through the tube, or it migrates into the end of the tube or it falls out," he said.

The US Food and Drug Administration provided figures regarding the types of complaints it had received on Essure.

In the FDA’s adverse reporting database, from 2002 through the end of October 2013, the agency reported 943 complaints related to Essure.

Of those adverse events, 606 related to pain, 140 were for hemorrhaging, 130 for headaches, 95 for menstrual irregularities, 88 for fatigue and 77 for weight malfunctions.

In an email, a spokesperson for the agency wrote, "The most frequent device problems reported were the migration of the device or device component (116), patient device incompatibility (113) (e.g., possible nickel allergy), device operating differently than expected (73), malposition of the device (46), and device breakage (37)."

Another complication that is apparently not present in the FDA data is pregnancy. 

Women who have joined forces with Brockovich have shared stories of unwanted pregnancy after getting Essure and shared their stories online.

Leila Cruz, a 29-year-old mother of three from Jacksonville, is pregnant with her fourth child despite having Essure implanted in 2007.

This is the second time Cruz has gotten pregnant on the device, she miscarried once in 2011. 

The FDA said its adverse event reporting data alone cannot be used to figure out just how often certain events, like pregnancy, are occurring.

Bayer purchased Essure from Conceptus, Inc. in 2013 and has stood by the safety and effectiveness of the product.

In written and video statements, the company points out that nearly 750,000 women worldwide have chosen Essure as their permanent birth control method.

Bayer pointed to the results of a five-year Essure study completed by the FDA, that overall "did not demonstrate any new safety problems or an increased incidence of problems already known."

In a summary of that five-year-report, the FDA writes, "To date, we have found no evidence in the literature indicating any new or more widespread complications definitely associated with Essure occurring more than five years after Essure placement."

Local 6 filed a Freedom of Information Act request to receive the full five year study completed by the FDA, but the request has not been returned at this time.

Meanwhile, Dr. McCaurus said he will continue to have honest conversations with his patients about the device and the potential problems.

"There's a lot of stakeholders in this process, we all have to collaborate, get the information to the patient, answers the patients questions and concerns and try to make a good decision," he said.