Effectiveness of aerobic exercise in the prevention and treatment of postpartum depression: Meta-analysis and network meta-analysis

Background Aerobic exercise is widely recognized for improving mental health and reducing negative emotions, including anxiety. However, research on its role in preventing and treating postpartum depression (PPD) has yielded inconsistent results. Some studies show positive effects on PPD symptoms, while others find limited impact, suggesting various factors at play, such as exercise type, intensity, and individual differences. To address this gap, our study aims to comprehensively gather evidence on the preventive and therapeutic effects of aerobic exercise for PPD. We’ll focus on differences in exercise program design and implementation, exploring how these factors impact intervention outcomes. By identifying effective exercise approaches, we aim to provide more comprehensive exercise prescription recommendations for this vulnerable population. Methods We conducted a quantitative systematic review of the study in 5 representative databases for the effect of aerobic exercise on PPD. Meta-analysis and network meta-analysis were performed with Review-Manager.5.4 and Stata.16.0 software, respectively. This study has been registered on the official Prospero website, and the registration code is CRD42023398221. Results Twenty-six studies with 2,867 participants were eventually included and the efficacy of aerobic exercise in preventing and treating postpartum depression is significant compared to standard care. (MD = -1.90; 95%CL: -2.58 to -1.21; I2 = 86%). Subgroup analysis suggests that the intervention objective (prevention vs. treatment) of exercise could potentially be a source of heterogeneity in this study, as the “Test for subgroup difference” revealed the presence of significant distinctions (p = 0.02<0.05). The “Test for subgroup difference” yielded non-significant results for both the supervised vs. unsupervised subgroup comparison (p = 0.55 > 0.05) and the individual vs. team subgroup comparison (p = 0.78 > 0.05). Nonetheless, when assessing their effect sizes [Subtotal (95%CL)], the supervised exercise group [-1.66 (-2.48, -0.85)] exhibited a slightly better performance than the unsupervised exercise group [-1.37 (-1.86, -0.88)], while the team exercise group [-1.43 (-1.94, -0.93)] slightly outperformed the individual exercise group [-1.28 (-2.23, -0.33)]. Network meta-analysis indicated that moderate intensity (35~45 min) group demonstrated a more pronounced intervention effect compared to low intensity (50~60 min) group [-2.63 (-4.05, -1.21)] and high intensity (20~30 min) group [-2.96 (-4.51, -1.41)], while the 3~4 times/week group had a more significant intervention effect compared to 1~2 times/week groups [-2.91 (-3.99, -1.83)] and 5~6 times/week groups [-3.28 (-4.75, -1.81)]. No significant differences were observed in pairwise comparisons of intervention effects among the five common types of aerobic exercises. (95%CL including 0). The Surface Under the Cumulative Ranking curve (SUCRA) results align with the findings mentioned above and will not be reiterated here. Conclusion The efficacy of aerobic exercise in preventing and treating postpartum depression is significant compared to standard care, with a greater emphasis on prevention. The optimal prescribed exercise volume for intervention comprises a frequency of 3~4 exercise sessions per week, moderate intensity (35~45 minutes). Currently, several uncharted internal factors influence the optimal intervention effect of aerobic exercise, such as the potential enhancement brought by team-based and supervised exercise. Given the absence of significant differences in certain results and the limitations of the study, it is essential to exercise caution when interpreting the outcomes. Further research is needed in the future to provide a more comprehensive understanding.

Give the name and affiliation of any individuals or organisations who are working on the review but who are not listed as review team members.NOTE: email and country must be completed for each person, unless you are amending a published record.

* Review question.
State the review question(s) clearly and precisely.It may be appropriate to break very broad questions down into a series of related more specific questions.Questions may be framed or refined using PI(E)COS or similar where relevant.
Aerobic exercise is medicine for the prevention and treatment of postpartum depression, however, little is known about the most efficacious amount of exercise and the exercise protocol.This review aims to provide recommendations for the design and implementation of exercise prescription in this population.

* Searches.
State the sources that will be searched (e.g.Medline).Give the search dates, and any restrictions (e.g.language or publication date).Do NOT enter the full search strategy (it may be provided as a link or attachment below.) Search strategy was conducted in these domestic and international databases: China National Knowledge Infrastructure (CNKI), Wanfang Database, MEDLINE, ScienceDirect, PubMed.We searched for all randomized controlled trial studies on exercise interventions for PPD, and identified keywords.

URL to search strategy.
Upload a file with your search strategy, or an example of a search strategy for a specific database, (including the keywords) in pdf or word format.In doing so you are consenting to the file being made publicly accessible.
Or provide a URL or link to the strategy.Do NOT provide links to your search results.

* Participants/population.
Specify the participants or populations being studied in the review.The preferred format includes details of both inclusion and exclusion criteria.
Participants: patients /potential patients with postpartum depression Inclusion criteria: the subjects included women with diagnosed PPD or at risk for PPD during the perinatal period Exclusion criteria: the population with depression except for pregnant women 第4页 共9页 2023/2/16 14:29

* Intervention(s), exposure(s).
Give full and clear descriptions or definitions of the interventions or the exposures to be reviewed.The preferred format includes details of both inclusion and exclusion criteria.
Exercise interventions：As a new "prescription tool", exercise interventions are not only an important nonpharmacological method in treating postpartum depression, but also effective in preventing this disorder.Aerobic exercise as a common type of exercise for postpartum depression management.Current evidence supports that PPD can be effectively prevented and treated through exercise due to the postpartum-specific health outcomes including less urinary stress incontinence, less lactation-induced bone loss, reducing postpartum weight retention, and less anxiety and depression (Garnaes et al., 2019).It is widely recognized for the advantages of high practical operability and safety.Inclusion criteria: the exercise intervention type in the experimental group was aerobic exercise Exclusion criteria: Interventions were only psychotherapy and medication

* Comparator(s)/control.
Where relevant, give details of the alternatives against which the intervention/exposure will be compared (e.g.another intervention or a non-exposed control group).The preferred format includes details of both inclusion and exclusion criteria.
All control groups were usual care

* Types of study to be included.
Give details of the study designs (e.g.RCT) that are eligible for inclusion in the review.The preferred format includes both inclusion and exclusion criteria.If there are no restrictions on the types of study, this should be stated.
A randomized controlled trial (RCT) types of study to be included.

Inclusion criteria: RCTs
Exclusion criteria: Non-randomized controlled experimental study

Context.
Give summary details of the setting or other relevant characteristics, which help define the inclusion or exclusion criteria.

* Main outcome(s).
Give the pre-specified main (most important) outcomes of the review, including details of how the outcome is defined and measured and when these measurement are made, if these are part of the review inclusion criteria.
We performed meta-analysis of the mean EPDS scores of the experimental and control groups before and after the aerobic exercise intervention

Measures of effect
We performed meta-analysis of the mean EPDS scores of the experimental and control groups before and after the aerobic exercise intervention using RevMan 5.3 software.Effect values were counted using the mean difference (MD) and 95% confidence interval (CI) because the outcome indicators of all included studies were EPDS scale scores, which are continuous variables of the same measure.When the 95% CL included 0, it indicated no statistical significance.If I² ≤ 50% or p > 0.1 indicates less heterogeneity, a fixed-effects model was chosen.On the contrary I² >50% or p ≤ 0.1, it means that the heterogeneity is large, and a random-effects model should be used after analyzing the source of heterogeneity (e.g., sensitivity analysis or subgroup analysis).

* Additional outcome(s).
List the pre-specified additional outcomes of the review, with a similar level of detail to that required for main outcomes.
Where there are no additional outcomes please state 'None' or 'Not applicable' as appropriate to the review 第5页 共9页 2023/2/16 14:29 Measures of effect

* Data extraction (selection and coding).
Describe how studies will be selected for inclusion.State what data will be extracted or obtained.State how this will be done and recorded.
When heterogeneity is high, we need to go through a subgroup analysis with the aim of exploring the sources of heterogeneity and deriving a better protocol for the exercise intervention.After comparing the exercise guidelines of the studies, striking differences were found in factors such as timing of intervention, supervision or not, and form of exercise (individual or team), with significantly less heterogeneity between studies when grouped by these factors.However, subgroup heterogeneity remained high for timing of exercise intervention.Effect values were counted using the mean difference (MD) and 95% confidence interval (CI) because the outcome indicators of all included studies were EPDS scale scores, which are continuous variables of the same measure.When the 95% CL included 0, it indicated no statistical significance.If I² ≤ 50% or p > 0.1 indicates less heterogeneity, a fixed-effects model was chosen.On the contrary I² >50% or p ≤ 0.1, it means that the heterogeneity is large, and a random-effects model should be used after analyzing the source of heterogeneity (e.g., sensitivity analysis or subgroup analysis).When heterogeneity is high, we need to go through a subgroup analysis with the aim of exploring the sources of heterogeneity and deriving a better protocol for the exercise intervention.After comparing the exercise guidelines of the 26 studies, striking differences were found in factors such as timing of intervention, supervision or not, and form of exercise (individual or team), with significantly less heterogeneity between studies when grouped by these factors.However, subgroup heterogeneity remained high for timing of exercise intervention.

* Risk of bias (quality) assessment.
State which characteristics of the studies will be assessed and/or any formal risk of bias/quality assessment tools that will be used.
According to the preliminary risk assessment for publication bias as recommended by the Cochrane Collaboration, the following parameters were included: adequate random sequence generation, allocation concealment, blinding of participants and personnel, blinding of outcome assessment, incomplete outcome data, selective reporting and other biases.

* Strategy for data synthesis.
Describe the methods you plan to use to synthesise data.This must not be generic text but should be specific to your review and describe how the proposed approach will be applied to your data.
If meta-analysis is planned, describe the models to be used, methods to explore statistical heterogeneity, and software package to be used.
We performed meta-analysis of the mean EPDS scores of the experimental and control groups before and after the aerobic exercise intervention using RevMan 5.3 software.Effect values were counted using the mean difference (MD) and 95% confidence interval (CI) because the outcome indicators of all included studies were EPDS scale scores, which are continuous variables of the same measure.When the 95% CL included 0, it indicated no statistical significance.If I² ≤ 50% or p > 0.1 indicates less heterogeneity, a fixed-effects model was chosen.On the contrary I² >50% or p ≤ 0.1, it means that the heterogeneity is large, and a random-effects model should be used after analyzing the source of heterogeneity (e.g., sensitivity analysis or subgroup analysis).

* Analysis of subgroups or subsets.
State any planned investigation of 'subgroups'.Be clear and specific about which type of study or participant will be included in each group or covariate investigated.State the planned analytic approach.
when heterogeneity is high, we need to go through a subgroup analysis with the aim of exploring the sources of heterogeneity and deriving a better protocol for the exercise intervention.After comparing the exercise guidelines of the 26 studies, striking differences were found in factors such as timing of intervention, supervision or not, and form of exercise (individual or team), with significantly less heterogeneity between studies when grouped by these factors.
However, subgroup heterogeneity remained high for timing of exercise intervention。 Further observation of the intervention elements in this subgroup revealed that all studies in this subgroup also had differences in factors such as aerobic exercise program and amount of exercise ( intensity, duration, frequency, and total duration of intervention), due to the large number of influencing factors, the heterogeneity was high, Stata 16.0 software was used to perform a network meta-analysis and draw an evidence network diagram.As there was no closed loop in the evidence network diagram of this study, no inconsistency test was required and comparisons were made directly, and drew the league table (the data in the table represents the MD values and 95% CI values for direct two-by-two comparisons of different interventions.When MD<0, the "column" treatment measures were superior to the "row", and vice versa.When 95% CI don't included 0 , it indicated no statistical significance (p<0.05), and vice versa.Then, the Surface Under The Cumulative Ranking (SUCRA) of each intervention was calculated, and the higher the probability, the better the intervention effect.

* Type and method of review.
Select the type of review, review method and health area from the lists below.
Inclusion criteria: (1) the analysis type in the literature is a randomized controlled trial (RCT); (2) the subjects included women with diagnosed PPD or at risk for PPD during the perinatal period; (3) the exercise intervention type in the experimental group was aerobic exercise; (4) the Edinburgh Postpartum Depression Symptom Scale (EPDS) was used for the diagnosis of PPD in the included studies.Exclusion criteria: (1) review articles; (2) the population with depression except for pregnant women; (3) the nonexercise interventions.(4) Screening for postpartum depressive symptoms using other scales: The World Health Organization 5 Physical and Mental Health Indicators (WHO-5), Pittsburgh Sleep Quality Index (PSQI), Beck Depression Inventory (BDI), Hamilton Anxiety Inventory (HAMA); (5) inadequate trial data; (6) animal testing.

is complete 18. * Condition or domain being studied.
https://www.crd.york.ac.uk/PROSPEROFILES/398221_STRATEGY_20230209.pdfDo not make this file publicly available until the review