Frequency and timing of complications within the first postpartum year in the United States and Canada: A systematic review and meta-analysis.

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 one year postpartum in the United States and Canada. DATA SOURCES PubMed MEDLINE, Web of Science, EBSCO CINAHL, and the Cochrane CENTRAL and Database of Systematic Reviews were reviewed from January 1, 2010, until 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 less than 100 patients, not reporting the timing of evaluation, or only included patients with a specific medical condition (e.g. preeclampsia) were excluded. STUDY APPRAISAL AND SYNTHESIS METHODS Data screening, extraction, and appraisal were performed by two reviewers. The appraisal tool was the Joanna Briggs Institute instrument for studies reporting prevalence data. Meta-analysis using random effects modelling was performed if a complication was reported in two or more studies. RESULTS Out of 4874 retrieved articles, 117 were included (93 original investigations, 24 reviews). The total sample size from original investigation studies was 246,521,464 patients (median (interquartile range) 6,030 (513 to 327,066) per study). In total, 41 complications and mortality data were extracted, with significant heterogeneity amongst definitions and time points of measurements. The one-year postpartum frequency estimates from meta-analysis (per 10,000, with 95% confidence interval) were anxiety 1,380 (845 - 2,174), depression 1008 (749 - 1,343), hypertension 890 (345 - 2,109), obsessive compulsive disorder 996 (134 - 4,089), hemorrhage 591 (454 - 763), post-traumatic stress disorder 464 (188 - 1,100), surgical infection 581 (12 - 7,678), 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 (0.2 to 1.0), acute myocardial infarction 0.25 (0.06 - 1.03), and mortality 1.2 (0.3 - 5.6). CONCLUSIONS We report frequencies and timings for 41 complications and mortality from delivery to one year postpartum. Of the nine complications that underwent meta-analysis, anxiety, depression, hypertension and hemorrhage were reported most frequently. These results can inform evidence-based resource allocation and guide optimal postpartum monitoring and care pathway development.