Fig 1.
An overview of the selection process for studies.
Table 1.
Characteristics of studies (n = 22).
Fig 2.
Risk of bias across 22 included studie.
Fig 3.
Forest plot showing the incidence of postpartum depression symptoms (PPDS) at 1 week.
CI: confidence interval; M-H: Mantel–Haenszel.
Fig 4.
Forest plot showing the incidence of postpartum depression symptoms (PPDS) at 4−6 weeks.
CI: confidence interval; M-H: Mantel–Haenszel.
Fig 5.
Funnel plot assessing publication bias in studies evaluating postpartum depression (PPD) risk.
Each point represents an individual study, plotted based on the effect size (horizontal axis) versus the standard error (vertical axis). The funnel plot’s asymmetry, evident in the uneven distribution of studies on either side of the mean effect size (solid vertical line), suggests the potential for significant publication bias. (a): Risk of PPD at one-week follow-up; (b) Risk of PPD at 4-6-week follow-up.
Fig 6.
Trial sequential analysis (TSA) for postpartum depression (PPD) risk at 1-week follow-up.
As illustrated, the z-curve crosses the TSA boundary, indicating that the accumulated evidence has achieved the requisite level of statistical significance and robustness, thereby affirming the reliability of the intervention observed. Additional trials are unlikely to alter this conclusion, underlining the sufficiency of the current evidence. The z-curve (blue line) represents the cumulative z-score as each trial is added sequentially. The TSA boundary (i.e., benefit boundary) signifies the adjusted threshold for statistical significance, taking into account repetitive testing on accumulating data.
Fig 7.
Trial sequential analysis (TSA) for postpartum depression (PPD) risk at 4–6-week follow-up.
As illustrated, the z-curve crosses the TSA boundary, indicating that the accumulated evidence has achieved the requisite level of statistical significance and robustness, thereby affirming the reliability of the intervention observed. Additional trials are unlikely to alter this conclusion, underlining the sufficiency of the current evidence. The z-curve (blue line) represents the cumulative z-score as each trial is added sequentially. The TSA boundary (i.e., benefit boundary) signifies the adjusted threshold for statistical significance, taking into account repetitive testing on accumulating data.
Table 2.
Subgroup analysis on the incidence of postpartum depression symptoms (PPDS).
Fig 8.
Meta-regression analysis of the influence of total dosage on postpartum depression (PPD) risk at (a) 1- and (b) 4–6-week follow-ups. The plot illustrates individual studies as points, positioned according to their respective total dosages (horizontal axis) and corresponding effect sizes measured as the risk of PPD (vertical axis). The sizes of the points represent the weight of each study in the meta-analysis. The solid line represents the regression line, indicating the relationship between total dosage and PPD risk.
Fig 9.
Forest plot showing differences in depression scores at 1-week follow-up.
CI: confidence interval; IV: invariance; Std: standardized.
Fig 10.
Forest plot showing differences in depression scores at 4–6-week follow-up.
CI: confidence interval; IV: invariance; Std: standardized.
Table 3.
Certainty of evidence based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.