How to predict natural conception in women underwent endometriosis surgery?

How to predict natural conception in women underwent endometriosis surgery?

Endometriosis fertility index can be used as a reliable staging system for the prediction of natural pregnancy following endometriosis surgery.

Key Points


  • The EFI score can be preferred for the postoperative consultation about getting pregnant in women seeking conception after endometriosis surgery.


  • The possibility of conception after endometriosis surgery is an important issue and the decision of whether or not using the assisted reproductive technology for these women needs an algorithm.

What’s done here?

  • This retrospective study evaluates the availability and reliability of Endometriosis Fertility Index (EFI) for the prediction of non-assisted reproductive technology pregnancy in women who underwent endometriosis surgery.
  • 374 women underwent surgery in a single center for endometriosis in the Republic of Korea (January 2009-February 2015) were included and calculations were based on the hospital’s records.
  • A total of 77 participants wished to get pregnancy, resulting in 33 natural and 9 ART conceptions. Authors selected only 68 women who attempted to conceive naturally for statistical analysis.
  • Revised American Fertility Society (rAFS) classification and EFI scores were calculated.
  • After all operative interventions, gonadotropin-releasing hormone analogs for 3–6 months were prescribed to patients. Then they were attempted to conceive naturally.
  • All women were monitored until the pregnancy occurred.
  • Receiver-operating characteristic (ROC) curves and the area under the curve (AUC) were used for the ability of rAFS and EFI to predict pregnancy outcomes.

Key results:

  • Thirty-three of 68 patients conceived without the need for ART.
  • The median EFI score was 6.13±0.25, the mean EFI values of non-pregnant and pregnant women were 5.43±0.37 and 6.88 ± 0.28, respectively.
  • The strong predictors for the prediction of pregnancy were age, EFI, body mass index (BMI), and other historical factors. rAFS score was not associated with obstetric outcome in this population.
  • Based on the ROC curve, the cut-off level for EFI to predict positive pregnancy outcome was 6. When EFI score value was higher than 6, the pregnancy rate increased.

Strengths and Limitations

  • The evaluation of EFI score to predict becoming pregnant naturally after endometriosis surgery in Korean women represents the , of this study.
  • The retrospective design reduces the accountability of EFI score calculations. Also, the small sample size, the absence of early evaluation of male infertility, and most importantly, the reality that in clinical practice, the clinical decision for attempting ART being made by the patient's preference and their abilities to undergo IVF which may result in selection bias were the limitations of this study.

Lay Summary

Endometriosis is defined as the localization of endometrial glandular and stromal cells outside the uterine cavity. The most common symptoms are dysmenorrhea, dyspareunia, chronic pelvic pain, and infertility. The prevalence of endometriosis increases in the infertile population. Thus, the important issue for most women is the probability of getting pregnant,  especially following endometriosis surgery.

Several classification and scoring systems have been introduced to clinicians’ use, one of the most frequently used is the rAFS score. However, this scoring system cannot be applied for the prediction of pregnancy after surgery. Upon this, EFI score has been developed in 2010 which has the ability to predict obstetric outcomes after surgery.

Endometriosis Fertility Index(EFI) score is a summary of historical factors including age, infertility duration, obstetric history and surgical factors including rAFS score, least function score at the end of surgery.

Kim et al, a group of scientists from Korea, published a retrospective study titled as “Use of the Endometriosis Fertility Index to Predict Natural Pregnancy after Endometriosis Surgery: A Single-Center Study” in the journal Gynecological and Obstetric Investigation.

The authors sought to evaluate the ability of EFI score to predict fecundity after endometriosis surgery in Korean women. They found that EFI score is a reliable scoring system that can be used to predict pregnancy outcome following endometriosis surgery.

“The EFI scores can be used to guide postoperative treatment in women with endometriosis. However, other prognostic factors, including other causes of infertility and ovarian reserve, and socio-economic factors, including insurance coverage, economic status, and the accessibility of IVF, should also be considered in the management of women with endometriosis,” they added.

Research Source:

endometriosis infertility rAFS score EFI score pregnancy endometriosis surgery


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