Results Summary

What was the research about?

Each year, more than 345,000 women in the United States have procedures to permanently prevent pregnancy. These procedures have risks such as pain or bleeding. Also, some women need to have a repeat procedure.

In this study, the research team compared two procedures to prevent pregnancy for women who haven’t had a baby within six weeks:

  • Tubal ligation, often called getting your tubes tied. In this procedure, doctors burn, block, or remove the fallopian tubes. Tubal ligation is the most common permanent way to prevent pregnancy among US women.
  • Hysteroscopic sterilization with a device called Essure. In this procedure, a doctor places a metal coil in each fallopian tube. The coils cause scars, which block the tubes. Essure was offered from 2002 until 2018. Some people still rely on Essure to prevent pregnancy.

The research team compared how well the procedures worked to prevent pregnancy; they also looked at side effects.

What were the results?

Pregnancy rates after both procedures were higher than expected. Doctors expect less than 1 percent of women to get pregnant after these procedures.

After five years, compared with women who had tubal ligation, women who had Essure:

  • Had lower pregnancy rates. About 6 percent of women who had Essure had a pregnancy compared with 7 percent who had tubal ligation.
  • Were more likely to have a repeat procedure to prevent pregnancy.

After one year, compared with women who had tubal ligation, women who had Essure were:

  • More likely to have abnormal bleeding in the uterus
  • Less likely to have pelvic or stomach pain
  • Less likely to have surgeries to remove the uterus or ovaries

The two groups didn’t differ in whether women had:

  • Headaches, backaches, or pelvic inflammatory disease after one or five years
  • Pelvic pain, stomach pain, or other procedures after five years

Who was in the study?

The study included data from 29,871 women ages 18–50 in California who had procedures to prevent pregnancy between 2008 and 2014. All women had Medicaid. Of the women, 23,965 women had tubal ligation, and 5,906 women had Essure. Data were available for 10,352 of these women after five years.

Among the women, 51 percent were Hispanic, 30 percent were White, 8 percent were Black, 3 percent were Asian, and 7 percent reported other race. The average age was 33.

What did the research team do?

The research team reviewed insurance data for the women to see if they had a pregnancy or pregnancy-related claims after having Essure or tubal ligation.

Doctors and patients, including women who had Essure or tubal ligation, gave input on the study. They also asked the research team to explore results for women who had used intrauterine devices, or IUDs, to prevent pregnancy.

What were the limits of the study?

The study included women with Medicaid in California. Results may differ for other women.

Future research could look at procedures to prevent pregnancy that are done within six weeks after childbirth.

How can people use the results?

Although Essure is no longer offered, doctors and patients with Essure can use the results when making decisions about preventing pregnancy.

Final Research Report

View this project's final research report.

Peer-Review Summary

Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.

The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments. 

Peer reviewers commented and the researchers made changes or provided responses. Those comments and responses included the following:

  • The reviewers noted that this was a well-written report that was very accessible for various stakeholders. However, they did request that the researchers provide more information about the sterilization procedures compared in this study (hysteroscopic sterilization and laparoscopic sterilization). The researchers added more details about the procedures. They also explained that the brand name Essure refers to the specific hysteroscopic sterilization device that was available on the market and used by patients in this research.
  • The reviewers asked  whether the finding that women ued prescription contraception after undergoing a sterilization procedure indicated concern about sterilization failure. The researchers explained that women may use prescription contraception for menstrual symptoms such as heavy bleeding, pain, or premenstrual dysphoric disorder, but some of these symptoms also might have been related directly to the sterilization procedure itself. In this study, it was not possible to discern the reasons for using prescription contraception after sterilization.
  • The reviewers asked for more consideration of the limitations for observational data, including the fact that women were not randomly assigned to treatments and could have different characteristics that affected outcomes. For instance, the reviewers asked whether the researchers had any prior evidence to support the assertion that subsequent sexual and contraceptive behavior should be the same between women who underwent hysteroscopic sterilization and those who underwent laparoscopic sterilization. The researchers explained that they used propensity score methods to account for self-selection and the possibility of important differences between women in the two different interventions. They used multiple important variables, including contraceptive use, in calculating propensity scores, but they acknowledged that information about sexual activity was not available in the patient records; thus, the researchers did not have data to support their claim that sexual behavior should be the same for women in the two sterilization conditions. Further, the researchers acknowledged that given the identified subgroup differences for women from different cultural or ethnic groups,  cultural and community norms regarding sexual behavior and other unmeasured behaviors or beliefs could be confounding factors affecting study results. The researchers expanded their discussion of such factors in their revised report. 
  • The reviewers asked the researchers to provide references for their approach to handling missing data, and particularly, for not using multiple imputation methods as promoted in the PCORI Methodology Standards for Missing Data. The researchers expanded their discussion of missing data with references supporting their approach, which focused on sensitivity analyses. They reported that they had considered performing additional sensitivity analyses using multiple imputation with assumptions that missing data were not missing at random, but their small amount of missing data and lack of alternatives to missing data at random indicated that such additional work was unwarranted.

Conflict of Interest Disclosures

Project Information

Aileen M. Gariepy, MD, MPH
Yale University
Real World Effectiveness and Safety of Hysteroscopic (Essure®) Compared to Laparoscopic Sterilization

Key Dates

August 2017
January 2022

Study Registration Information


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Last updated: March 14, 2024