Reviewer ’s report  
 
Title: Nocturnal finger skin temperature in menstrual cycle trackin g: Ambulatory pilot study 
using a wearable Oura ring  
 
Version: 1 Date: 14 Jul 2019  
 
Reviewer: Helena Kopp Kallner  
 
Reviewer's report:  
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My main objections have been met and I agree with comments from other reviewers. At this 
point I leave comments to the other reviewers to their objection s. I have two last comments.  
 
1. To use any progestin/progesterone medication would really be unacceptable in this study as it 
definitely affects BBT during the time the woman tak es the progestin/progesterone. Would 
exclude that woman.  
2. 24/7 sound a bit  unscientific to me. Please revise. Suggest around the clock or without 
interruption.  
 
Are the methods appropriate 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 conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
Are you able to assess any stat istics in the manus cript or would you recommend an 
additional statistical review?  
If an additional statistical review is recommended, please speci fy what aspects require further 
assessment in your comments to the editors.  
 
I recommend additional statistical review  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Need s some language corrections before being published  
 
Declaration of competing interests  
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below. If your reply is yes to any, please give details below.  
 
I am on the advisory board of Natural Cycles.  
 
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I agree to the open peer review policy of the journal