Title: Combined oral antibiotics and intrauterine perfusion can improve in vitro fertilization and
embryo transfer pregnancy outcomes in patients with chronic endometritis and repeated embryo
implantation failure
Version: 3 Date: 13 Mar 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)?
Yes - there is a clear objective
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?
Not sure - I am not able to assess the statistics in this 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: This is a small, retrospective study that compares  uterine perfusion
to controls in patient with repeated implantation failure and endometritis prior to embryo transfer
and looks at pregnancy outcomes.
The study has such few participants that drawing any conclusions from this study is
inappropriate.
REQUESTED REVISIONS:
The retrospective design of this study means that any results are susceptible to significant bias
and any conclusions based on these results are unlikely to be reliable. The authors have not
explained how the data was obtained. How did they know how to find these 88 patients? Do
the have a database where they searched for recent patient with CE, did they combine this
with a separate search for RIF? I cannot understand what the patients consented to if it was a
retrospective study. Why not do a prospective, randomised study - with such small numbers and
such tight inclusion criteria, I think a randomised controlled trial (RCT) would be the only way
to do this study.
ADDITIONAL REQUESTS/SUGGESTIONS:
In the abstract under Conclusion: ""to our knowledge"" is poor English and should be removed
Under Background: 'impregnated 3 patients' is not a clear phrase. Also Gentamicin is 'sensitive'
should perhaps be 'effective'. It is the bacteria that are sensitive not the antibiotics.
Methods: '3 ET's with excellent embryos' What is an excellent embryo? Do you mean 'better
than average', perhaps a grading and grading system would be more appropriate.
Section 2.3 : Oral Metronidazole is usually 400mg , was this definitely 500mg?
And in that same section and on that same line 'according to each patients will' - this is not
randomisation, or clinically based decision making - perhaps provide and explanation of what
the patient was told and how they decide to have the infusion or not.
Section 2.3 last paragraph. A D3 transfer is usually cleavage stage and D4 is usually Morula
Section 3.4: the rate of miscarriage in each arm a 6.667% (n=20) and 4.545% (n=22) represents
one miscarriage in each arm. I have not done the stats myself but that does not seem statistically
significant to me and is definitely not clinically significant."