Essure was designed to replace, or drastically undercut, the use of tubal ligation, a collection of surgical procedures intended to sever or block a woman’s Fallopian tubes.

Patients Question Essure’s Ability To Prevent Pregnancy

Before Essure – a birth control implant – was approved, women had few options in the realm of permanent contraception. Tubal ligation was really the only choice, but it was a choice often marked by invasive surgical procedures, along with the risks that attend surgery. That’s why many members of the medical community hailed Essure’s approval in 2002 as a significant step in the right direction.

Rather than tying, cutting, clipping or burning the Fallopian tubes, doctors could now insert two small implants – and wait for an accumulation of scar tissue to block the tubes permanently. Essure was portrayed as a non-surgical procedure, with few side effects and incredible efficacy. Today, tens of thousands of women say that the promises made by Essure’s manufacturer were a lie.

Essure & Pregnancy Prevention Infographic

These women have amassed a startling array of evidence – from clinical trial data that was apparently concealed from the FDA to personal reports of severe pain, menstrual abnormalities and autoimmune disorders – in support of their allegations. But the implant’s effectiveness has also been called into question.

Hundreds of women have now filed lawsuits against Bayer, the German multinational who makes Essure. In a select number of these cases, patients say they became pregnant after receiving the implants, and accuse Bayer of overselling the device’s ability to prevent pregnancy.

Essure Promise & Reality Very Different, Yale Researcher Says

Aileen Gariepy, assistant professor of Obstetrics, Gynecology and Reproductive Sciences at the Yale School of Medicine, has been instrumental in peeling back the layers of questionable promises surrounding Essure. In 2014, she published a major study on the true efficacy of Essure in the journal Contraception, which found that the implants are less effective in preventing pregnancy than traditional methods of permanent contraception.

Study co-author Mitchell Creinin says that “when Essure was first approved by the Food and Drug Administration in 2002, data presented to physicians and patients only included those women who successfully completed all of the steps to be sterilized using the procedure.” But that’s not the whole story, Creinin told the University of California at Davis in 2014. Doctors have come to learn that Essure will never “take” in some patients. Placement of the implants in both Fallopian tubes is only successful in around 8 or 9 out of 10 patients. When we leave out those women who can’t be implanted successfully, Creinin argues, we end up with an inaccurate picture of Essure’s failure rates – one that could drastically inflate the implant’s ability to prevent pregnancy.

There’s a big difference, Gariepy says, between Essure’s efficacy under “perfect” circumstances, and how well the implants work in a “typical” situation.

Getting The Whole Story

But that’s not the distinction many studies on the efficacy of Essure have shown. In most studies, like a 2013 Spanish paper that heralded Essure as “the most effective permanent birth control system to date,” women in whom the device can’t be implanted successfully just aren’t counted as a failure of the implant itself.

Along with Yale’s Aileen Gariepy MD, Creinin set out to discover how many patients in the real world wouldn’t be able to rely on Essure. In a striking example of how two analyses of the same study data can lead to drastically different findings, the team used information that had already been published in the medical literature – but rather than artificially filtering out patients in whom implantation had failed, they kept them in.

Computer models allowed the researchers to take into account a much wider range of possible outcomes, from failed implantation procedures to problems in the three-month check-up intended to confirm an implantation’s success.

Higher Failure Rate In Real-World Circumstances

Their results are troubling. While a laparoscopic tubal sterilization only fails in around 3 to 7 out of every 1,000 women, the team found that Essure would lead to pregnancy in between 8 and 19 times as many patients – 57 out of every 1,000 women who receive the implants. The risk of pregnancy, the researchers concluded, is around 5.7% for every year that the device remains implanted.

Pregnancy Test

In a more recent article, Gariepy renewed her attack on the incomplete science behind early claims of Essure’s extraordinary effectiveness. She called out a 2015 data analysis, conducted by the FDA, in which the implants were found to be 100% effective over a five-year period. As Gariepy points out:

“five-year follow-up was completed in only 71% of women who underwent implantation (366 of 518). Women who did not have a successful bilateral Essure placement, became pregnant before the 3-month hysterosalpingogram, or underwent subsequent hysterectomy were excluded from the effectiveness analysis. Althought the FDA’s postapproval website states that ‘one of the strengths of the studies is the observed follow-up rates,’ the 71% rate suggests that adverse events, including unintended pregnancies, were probably missed and would affect interpretation of study findings.”

Gariepy’s conclusions were simple: “the evidence suggests that [Essure] is neither as effective nor as safe as the premarketing-approval evaluation indicated.”