Title: Physical activity and sleep quality among pregnant women during the first and second
trimesters are associated with mental health and adverse pregnancy outcomes
Version: 1 Date: 25 Dec 2023
Reviewer's report:
Review in BMC BMC Women's Health
"Effects of physical activity and sleep quality among healthy pregnant women during the first
and second trimesters on mental health and pregnancy outcomes”
1. General comments
The purpose of this study was to assess the association of physical activity and sleep quality with
mental health and pregnancy outcomes among healthy women at the first and second trimesters
of pregnancy. The study includes 268 participants and valid and reliable measurements of
physical activity, sleep quality, metal health and pregnancy outcomes. The manuscript adds
evidence to the hypothesis that physical activity and sleep quality are associated with mental
health and pregnan-cy adverse events. The manuscript is well written, but there are some specific
comments that I would like to point.
2. Specific comments
Title
Could be improved and made to be more stand out by stating what the study found, rather than
starting with 'Effects of …’. Indeed, I suggest the authors to remove the word ‘Effects’ from the
title since the study methodology does not allow to identify cause-effect relationships. Authors
can try with ‘Associations of …’
Please, write independent variables, dependent variables, and study population in that order in
the title.
Background
Please, focus on physical activity rather than exercise in order to get consistency with your meth-
ods and results. Furthermore, authors should introduce the relationship between physical activity
and pregnancy adverse outcomes in the end of the paragraph.
Please, state the hypothesis of the study in the last paragraph.
Methods
Please, specify the procedure and tools for clinical data measurements.
Please, include Spearman correlation and Kapla-Meier analysis subsections inside of statistical
analysis.
Statistical analysis
When sample size I higher than 50, Kolmogorov-Smirnov test should be implemented rather
than Shapiro-Wilk. Please, check normality again and run parametric or non-parametric test
according-ly.
A limitation of the Kaplan-Meier method is that it only provides unadjusted probabilities of ad-
verse outcomes. Pregnancy adverse outcomes might be affected by baseline data such as body
mass index, blood pressure, fasting blood glucose, …, so I guess the authors have obtained the
hazard ratios from Cox regression analyses considering these covariates. If so, it should be stated
clearly in the statistical analysis section with the including covariates. If Cox regression analyses
have not been run, authors should perform and report them.
Results
Please, report how many participants (or percentage) achieved the World Health Organization
rec-ommendation for physical activity in each trimester and show the data in Table 2.
Figure 2
Please, be consistent with the colour of each category. Figure 2A shows MI < 7.5 as blue colour,
whereas Figure 2B shows MI < 7.5 as orange colour. Please, indicate which trimester represents
each plot.
Discussion
Please, try to be more straightforward in the first paragraph by only reporting the findings of
your study and the clinical impact that might have.
Second paragraph, line eight: write ‘e’ in the word ‘the’.
Third paragraph, line four: Please, avoid reporting information about post-partum period and
fo-cus only on pregnancy since your data is from pregnancy period only.
Third paragraph, line eleven: As mentioned before, try to focus on physical activity rather than
exercise to get consistency.
Third paragraph: Is there another study examining the association of physical activity and
sleep quality with mental health different trimesters? Please, compare your results (significant
and non-significant) with other results from similar studies. I suggest the authors to divide
this paragraph in two paragraphs addressing physical activity and sleep quality separately and
deeply.
Fourth paragraph: Please, avoid the term exercise throughout the manuscript.
Please, include the strengths and limitations paragraph in the end of the discussion. It can be a
subsection of the discussion.