Title: The effect of chronic endometritis and treatment on patients with unexplained infertility
Version: 1 Date: 24 May 2023
Reviewer's report:
"PEER REVIEWER ASSESSMENTS:
OBJECTIVE - Full research articles: is there a clear objective that addresses a testable research
question(s) (brief or other article types: is there a clear objective)?
No - there are major issues
DESIGN - Is the current approach (including controls and analysis protocols) appropriate for
the objective?
No - there are major issues
EXECUTION - Are the experiments and analyses performed with technical rigor to allow
confidence in the results?
No - there are major issues
STATISTICS - Is the use of statistics in the manuscript appropriate?
No - there are issues with the statistics in the study
INTERPRETATION - Is the current interpretation/discussion of the results reasonable and not
overstated?
No - there are major issues
OVERALL MANUSCRIPT POTENTIAL - Is the current version of this work technically
sound? If not, can revisions be made to make the work technically sound?
Maybe - with major revisions
PEER REVIEWER COMMENTS:
GENERAL COMMENTS: I read carefully the manuscript ""The effect of chronic endometritis
and treatment on patients with unexplained infertility"". Although the efforts of the authors
are clear, there are several methodological elements that need to be clarified in order to have
a proper data interpretation. In addition, I have serious concerns about the novelty of this
investigation, since several previous trials studies the same outcomes in larger populations with
chronic endometritis.
REQUESTED REVISIONS:
Authors should take into account the following recommendations:
- The whole text needs language editing by a native speaker in order to improve grammar and
style.
- Introduction: authors should discuss novel pieces of evidence and highlight current gaps in the
diagnosis and management of chronic endometritis (they may refer to: PMID: 31710184).
- Introduction: to the best of my knowledge, several previous studies have investigated similar
parameters in women with chronic endometritis, even on larger cohorts. From this perspective,
the authors should clarify the novelty of their study (if any).
- Introduction: I would suggest to remark that the endometrial biopsy technique plays a key role
for the diagnosis of chronic endometritis, and it should be performed by hysteroscopy-guide as
recommended by current guidelines (they may refer to: PMID: 37061093).
- Methods: the authors declared “Both groups underwent hysteroscopy and
immunohistochemical tests for CD38 and CD138”. Few lines below, they declared exactly
the opposite: “58 patients with unexplained infertility who had not received hysteroscopy and
immunohistochemical detection of CD38 and CD138 were selected as the unexamined group”.
How did the authors know that this group, used as control, does not have chronic endometritis
too, if it did not undergo hysteroscopy and endometrial biopsy? This represents a serious bias
of the study.
- Methods: what about sample size calculation? I could not find any information about this point.
If sample size analysis was not performed, the study may be underpowered to detect significant
differences for the investigated outcomes.
- Methods: did the authors exclude endometriosis and/or endocrinological diseases in the case
and control groups?
- Methods: it is not clear whether the patients searched for spontaneous pregnancy or underwent
assisted reproduction. In the latter case, the authors should clarify: if they performed intrauterine
insemination, in vitro fertilization or intracytoplasmic sperm injection; the stimulation protocol
used; the oocyte/embryo evaluation (hoping that these procedures were consistent for the whole
cohort, both cases and controls, conversely this may represent another serious bias).
- Methods: does the study conform with the Strengthening the Reporting of Observational
Studies in Epidemiology (STROBE) Statement, validated by the Enhancing the QUAlity and
Transparency Of health Research (EQUATOR) network? If would have been mandatory to
conform with this international guideline standard. If they did not, they should explain the reason
why.
- Results: please reorganized the table with variables in the first column and groups in the next
ones, with p in the last column.
- Discussion: I recommend to discuss, at least briefly, the difference between “Impaired
inflammatory state of the endometrium” and “chronic endometritis” (PMID: 32802019), and the
results of a recent meta-analysis suggesting that the negative effects of chronic endometritis on
IVF outcome may be restricted to severe disease, whereas mild chronic endometritis may have
no influence on IVF success (PMID: 36140651)."