Title: Does the uterine microbiota affect the reproductive outcomes in women with recurrent
implantation failures?
Version: 2 Date: 27 Dec 2021
Reviewer:  Hassan S. O. Abduljabbar
Reviewer's report:
Does the uterine microbiota affect the reproductive outcomes in women with recurrent
implantation failures?
Keywords
infertility, assisted reproductive technologies, uterine microbiota, metagenomic sequencing,
embryo implantation
Generally
Does the uterine microbiota affect the reproductive outcomes in women with recurrent
implantation failures? (The title reflects the study.)
The subject involve san important subject in reproductive endocrinology
The study is (Not Original),
Fu M, Zhang X, Liang Y, Lin S, Qian W, Fan S. Alterations in vaginal microbiota and associated
metabolome in women with recurrent implantation failure. MBio. 2020 Jun 2;11(3):e03242-19.
Franasiak JM, Alecsandru D, Forman EJ, Gemmell LC, Goldberg JM, Llarena N, Margolis C,
Laven J, Schoenmakers S, Seli E. A review of the pathophysiology of recurrent implantation
failure. Fertility and Sterility. 2021 Dec 1;116(6):1436-48.
The message of the study will add  knowledge of the medical literature.
Abstract
The abstract reflects the study.
It is easy to understand.
It is a good summary.
It is well written.
The aim of our study was to evaluate the influence of the uterine microbiota on the embryo
implantation success in patients undergoing assisted reproductive technologies.
Background
Inefficiency of in vitro fertilization (IVF)programs can be caused by implantation failures.
The uterine microbiota can influence the implantation process.
However, it still remains unclearwhether opportunistic microorganisms detected in the
endometrium have a negative impact on the implantation success.
It is easy to understand.
It is a good summary.
Methods
The study included 130 women diagnosed with infertility.
The patients were divided into three groups:
group I included women with the first IVF attempt (n=39);
group II included patients with recurrent implantation failure following embryo transfer with
ovarian stimulation (n=27);
group III consisted of women with recurrent implantation failure following frozen-thawed
embryo transfer (n=64).
We performed microbiological examination of the embryo transfer catheter which was removed
from the uterine cavity after embryo transfer; cervical discharge of all the patients was
studied as well. Thirty patients were selected for meta genomic sequencing.
Results:
The study showed that the uterine cavity is not free of microorganisms.
A total of 44 species of microorganisms were detected:
26 species of opportunistic organisms and
18 species of commensals (14 species of lactobacilli and 4 species of bifidobacteria).
Obligate anaerobic microorganisms and Gardnerella vaginalis were detected more frequently
in group I comparedto group III(strict anaerobes – 15.4 and 1.6%; G. vaginalis - 12.8 and
1.6%,respectively) (p<0.05).
However, this fact did not have a negative influence on the pregnancy rate: it was 51.3% in
group I, it was 29.6% and 35.9% in women with recurrent implantation failures, respectively.
Conclusion
Opportunistic microorganisms which were revealed in low or moderate titers (103-105 CFU/
ml) in the uterine cavity and cervical canal did not affect the pregnancy rate in the women in
the study groups. The microflora of the uterine cavity and cervical canal differed in qualitative
composition in 87.9% of patients, therefore, we can suggest that the uterine cavity may form its
own microbiota. The microbiota of the uterine cavity is characterized by fewer species diversity
compared to the microbiota of the cervical canal.
Summary
The study is written in simple (English language with few spelling and grammar mistakes.)
Introduction good summary
Observational study
Sample size ?? how did you calculate the sample
130
Rational behind dividing them ???
The 1 tables and 4 figures illustrate the results
The Plagiarism .. There are some sentences in the manuscript taken from the web
Ethically approved
No conflicts of interests
Statistical analysis is basic
Total of 22 references most are old before 2010 and some not (validated or not checked)
The conclusion is clear for the reader. Small number of cases How can this help ???