Reviewer ’s report  
 
Title: Relationship between caffeine intake and infertility: a systematic review of controlled  
clinical studies  
 
Version: 1 Date: 01 Mar 2020  
 
Reviewer: Erdinç Sar ıdogan  
 
Reviewer's report:  
 
Please include all comments for the authors in this box rather than uploading your report as an 
attachment. Please only upload as attachments annotated ve rsions of manuscripts, graphs, 
supporting materials or other aspects of your report which cannot be included in a text format.  
 
Please overwrite this text when adding your comments to the authors.  
 
 
Dear authors,  
 
caffeine intake and fertility results are an  important and controversial issue. However, it has been 
known for over twenty years that high doses of caffeine can be harmful to conception and 
pregnancy outcomes (https://www.ncbi.nlm.nih.gov/pubmed/8575347). Article is well designed 
and written (requir ed two corrections stated end of the review). The title reflects the content well. 
Essential and encouraging information is provided in the abstract. Keywords conform to medical 
subject headings. Methods are explained sufficiently. Flowchart and checklist are available. 
Results are shown by figures and tables. GRADE method is used for recommendations. The 
limitations of the study are mentioned in the discussion. The authors made recommendations 
parallel to the guideline of the American Association for Repro ductive Medicine 
(https://www.ncbi.nlm.nih.gov/pubmed/28228319). Moreover, the authors indicated that further 
high quality studies are required for higher grade recommendations. I believe that this review of 
the authors will attract attention and will cont ribute to further work along with their previous 
review. I recommend acceptance of this quality paper.  
1. Kindly write "NOS" without abbreviation in the abstract section.  
2. Kindly write "achieved9points" separately in the line of 235.  
 
 
 
 
 
 
Are the methods appr opriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusio ns drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manuscript or would you recommend an  
additional statistical review?  
If an additional statistical revie w is recommended, please specify what aspects require further  
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an  
organisation that may in any way gain  or lose financially from the publication of this  
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose  
financially from the publication of this manuscript, either now or in the fut ure? 
 
3. Do you hold or are you currently applying for any patents relating to the content of the  
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization that 
holds  or has applied for patents relating to the content of  the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
If you can answer no to all of the above, write 'I declare that I have no competing interests' 
below.  If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests.  
 
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on my report to the authors and, if the manuscript is acc epted for publication, my named report  
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to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal