Short Nighttime Sleep Duration and High Number of Nighttime Awakenings Explain Increases in Gestational Weight Gain and Decreases in Physical Activity but Not Energy Intake among Pregnant Women with Overweight/Obesity

Round 1

Reviewer 1 Report

This paper addresses an important topic: sleep behaviors during pregnancy in relation to energy intake, PA, and GWG. Please review the paper to address the following:

Introduction:

The introduction is very long. Some parts of the intro are not necessarily relevant, it can easily be trimmed by 1/2 a page.

Line 52: Authors indicate that sleep behaviors have not been extensively studied in relation to pregnancy outcomes...not sure why this is being indicated when this is not exactly the topic of this paper. Also important to specify that you are looking at maternal outcomes.

Second sentence of the introduction does not really make sense and should be deleted. Poor sleep behaviors lead to sleep disturbances?

line 98: instead of device-based measurement, you should say "objectively assessed sleep using wrist actigraphy"

METHODS:

Upon reading the abstract, I thought that this was a pilot observational study but it seems this is a post hoc analysis of data from a clinical trial. This should be communicated in the abstract. I generally felt that the abstract was missing important points on methods and results.

Given that you are using data from a clinical trial, I think it is important to indicate what the intervention vs. control conditions were, even if this is a post hoc analysis. The reader needs to be informed of the intervention details to better interpret your results and evaluate your analytic approach. Please describe the intervention vs. control conditions.

I am confused by the device used to ascertain sleep....Is the Jawbone wrist worn activity monitor a commercial tracker? The authors indicate that it was compared to a Fitbit. How does it compare to actigraphy and polysomnography, the gold standard for assessing sleep? Would be good to include those validation studies and the estimate for sensitivity and specificity since you are not using the Actiwatch (which is a research grade validated device).

RESULTS & DISCUSSION

Try to minimize the use of abbreviations such as "ES" for example. Excessive abbreviations make the paper hard to read.

The discussion was good overall. It is important to acknowledge that you may have not observed an association with energy because this was a secondary outcome and you were underpowered. Some studies show that sleep quality is related to energy intake in women (cite JAHA study by Zuraikat et al. 2020), but indicate that this needs to be extended to pregnant women in better powered studies. 

In limitations, you should also indicate that you do not have any objective measures of energy balance. Also you do not acknowledge that you are not using a research grade accelerometer for the measurement and how the use of a commercial device may have influenced the estimation of sleep and PA.

Similarly, what about the strengths and limitations regarding measurement of diet?

I found your conclusions too strongly worded. This study has a small sample size, a lot of work needs to be done before we can determine causality. 

 

Author Response

Thank you for the opportunity to revise and resubmit our manuscript to Clocks & Sleep. We have outlined each comment and our author reply in the document attached. In the manuscript, we have noted major changes in red font within the body of the manuscript.

Author Response File: Author Response.pdf

Reviewer 2 Report

I am really pleased to review the manuscript entitled “Short Nighttime Sleep Duration and High Number of Nighttime Awakenings Explain Increases Gestational Weight Gain and Decreases in Physical Activity but Not Energy Intake Among Pregnant Women with Overweight/Obesity”

The topic of this manuscript falls within the scope of Clocks & Sleep.

The paper was well written and the authors decided to perform a secondary analysis of a large national trial on a relevant hot topic. However, several minor concerns could be retrieved while reading the paper, most importantly is in its readability.

1) Introduction

The greater part of the introduction is based on comparison with existing literature and extensive description of published findings. Authors should shorten the section synthesizing available evidences and lacks of current literature that brought to perform this analysis, while comparisons with existing literature should be moved to Discussion section. Weakest part of the discussion are from L80-100 and L-101-128

2) Methods

Well written, clear and concise.

3) Results

Well written. Authors should only avoid to replicate contents between Tables and text.

4) Discussion

Should be integrated with comparisons with existing literature moved from the Introduction. No other concerns have been underlined.

 

 

Author Response

Thank you for the opportunity to revise and resubmit our manuscript to Clocks & Sleep. We have outlined each comment and our author reply in the document attached. In the manuscript, we have noted major changes in red font within the body of the manuscript.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Thank you for addressing the comments. The manuscript is improved. A couple of minor edits.

Line 189: There is a typo, please fix to "polysomnography in non-pregnant women" i.e. delete one of "in" and "a". I think you can add a sentence about comparison to wrist actigraphy since it is a wearable, if a study is available for that.

Line 418: delete "lastly". It appears again in the same paragraph in line 422.

Line 437-438: "and why waking up during the night may be advantageous" makes no sense as written. An intervention for that? I think I am missing the point because of how this sentence is worded. Please fix this statement and consider breaking it into two sentences for more clarity. It is too long.

Author Response

Thank you for your comments and have all been addressed within the manuscript using tracked change. The line-by-line responses have been included as an attachment.

Author Response File: Author Response.pdf