Preoperative Neutrophil-to-Lymphocyte Ratio for prediction of postoperative pregnancy

Preoperative Neutrophil-to-Lymphocyte Ratio for prediction of postoperative pregnancy

Spontaneous fertility rate after laparoscopic excision of endometrioma could be predicted using preoperative serum Neutrophil‑to‑Lymphocyte Ratio level.

Key Points


  • Preoperative Neutrophil‑to‑Lymphocyte Ratio is associated with postoperative spontaneous pregnancy, depending on the inflammatory and immunologic pathogenetic basis of endometriosis.  


  • The usefulness of the NLA scoring system which combines the Neutrophil‑to‑Lymphocyte Ratio will benefit endometrioma patients to predict postoperative natural pregnancy.

What’s done here?

  • A single-center retrospective study was conducted at a tertiary referral center for endometriosis and reproductive surgery.
  • Infertile women with endometrioma who underwent laparoscopic excision by the experienced surgical team were enrolled for this study.
  • A standardized laparoscopic stripping technique was performed. The primary outcome was the postoperative spontaneous pregnancy rate.
  • Neutrophil‑to‑Lymphocyte Ratio and the NLA scoring system (combined Neutrophil‑to‑Lymphocyte Ratio, least function score, and age) were used for prediction.

Key results:

  • A total of 213 women were included, more than 90 percent were Stage III-IV by the rASRM.
  • More than half got pregnant spontaneously during the postoperative period, with a live birth rate of 47.9%.
  • Multivariate analysis showed that age, least function score, and Neutrophil‑to‑Lymphocyte Ratio level are independent predictors to predict spontaneous pregnancy.
  • The NLA scoring system, combining neutrophil‑to‑lymphocyte ratio, least function score, and age, was also found to be a predictor of postoperative spontaneous pregnancy.

Strengths and Limitations:

  • Assessment of the preoperative neutrophil‑to‑lymphocyte ratio level to predict natural pregnancy in infertile patients with endometrioma was the main strength.
  • Retrospective and single-center designs are limitations. Short follow-up and non-exclusion of other inflammatory diseases are other limitations. Other markers of ovarian reserve, such as antral follicle count and anti-Mullerian hormone, were not evaluated.

Lay Summary

Among women with endometriosis, 30 to 50 percent are estimated to have infertility, and 25-50% of infertile patients are found to have endometriosis. Anatomic distortion, diminished tubal peristalsis, diminished sperm movements, dysfunctional folliculogenesis, luteal phase dysfunctions, and alterations in endometrial receptivity have been proposed as the underlying mechanisms of endometriosis-associated infertility.

Several classification systems have been developed to identify the severity of endometriosis, but pregnancy outcomes could not be predicted using these systems. Endometriosis Fertility Index (EFI) could only be accepted as the prediction system for getting pregnant in endometriosis patients. However, patients should be operated on for this score.

Lin et al., a group of scientists from China, published a study titled “Preoperative neutrophil-to-lymphocyte Ratio Level is a Predictor of Postoperative Fertility in Infertile Patients with Ovarian Endometrioma” in the journal "Reproductive Sciences". The authors aimed to develop a non-invasive scoring system for the prediction of natural pregnancy during the postoperative period in infertile patients with endometriosis.

They recognized that there was a significant association between preoperative neutrophil-to-lymphocyte ratio levels, the higher ratio corresponding to the higher postoperative natural pregnancy. In addition, they created a new prediction model, named The NLA scoring system, combining the neutrophil‑to‑lymphocyte ratio, least function score, and age. NLA scoring system was also found to be closely related to postoperative spontaneous pregnancy rate and to have better clinical value than EFI. This association was explained by the inflammatory and immunologic pathogenetic mechanisms of endometriosis.        

“Preoperative neutrophil-to-lymphocyte ratio level is strongly associated with natural pregnancy outcomes in infertile endometrioma patients who have undergone laparoscopic treatment. NLA scoring has significantly better predictive efficacy and can assist in the clinical decision-making process.” the authors added.

Research Source:

endometriosis endometrioma infertility Neutrophil-to-lymphocyte ratio pregnancy EFI NLA scoring


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