Frequency and timing of complications within the first postpartum year in the United States and Canada: a systematic review and meta-analysis
Bibliographic record
Abstract
OBJECTIVE: Understanding the rates and timing of postpartum complications can facilitate timely screening and management to reduce preventable morbidity and mortality. The aim of this study was to summarize the frequency (prevalence or incidence) and timing of complications from hospital delivery to 1 year postpartum in the United States and Canada. DATA SOURCES: PubMed MEDLINE, Web of Science, EBSCO CINAHL, and the Cochrane Central Register of Controlled Trials and Database of Systematic Reviews were reviewed from January 1, 2010 to December 31, 2024. STUDY ELIGIBILITY CRITERIA: Inclusion criteria were studies written in English reporting the frequency and timing of medical, procedural/surgical, and psychosocial complications in adults in the United States and Canada, from hospital delivery to 1 year postpartum. Studies with fewer than 100 patients, those that did not report the timing of evaluation, or those that included only patients with a specific medical condition (e.g., preeclampsia) were excluded. STUDY APPRAISAL AND SYNTHESIS METHODS: Data screening, extraction, and appraisal were performed by 2 reviewers. The appraisal tool was the Joanna Briggs Institute instrument for studies reporting prevalence data. Meta-analysis using random effects modeling was performed if a complication was reported in 2 or more studies. RESULTS: Of 4874 retrieved articles, 117 were included (93 original investigations and 24 reviews). The total sample size from original investigation studies was 246,521,464 patients (median [interquartile range] 6030 [513-327,066] per study). In total, 41 complications and mortality data were extracted, with substantial heterogeneity among definitions and time points of measurements. The 1-year postpartum frequency estimates from meta-analysis (per 10,000, with 95% confidence interval) were anxiety 1380 (845-2174), depression 1008 (749-1343), hypertension 890 (345-2109), obsessive-compulsive disorder 886 (135-4089), hemorrhage 591 (454-763), post-traumatic stress disorder 464 (188-1100), surgical infection 581 (12-7678), postpartum severe maternal morbidity 100 (38-260), venous thromboembolism 17 (13-24), sepsis 11 (8-15), cardiomyopathy 1.9 (0.5-6.8), severe sepsis 1.2 (0.2-9.0), cardiac arrest 0.9 (0.8-1.0), acute myocardial infarction 0.25 (0.06-1.03), and mortality 1.2 (0.3-5.6). CONCLUSION: We report frequencies and timings for 41 complications and mortality from delivery to 1 year postpartum. Of the 14 complications that underwent meta-analysis, anxiety, depression, hypertension, obsessive-compulsive disorder, and hemorrhage were reported to be the most frequent. These results can inform evidence-based resource allocation and guide optimal postpartum monitoring and care pathway development.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.005 | 0.019 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.010 | 0.029 |
| Bibliometrics | 0.005 | 0.009 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.001 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".