AbstractBackgroundFew studies have examined the associations between pregnancy and birth complications and long‐term (>12 months) maternal mental health outcomes.ObjectivesTo review the published literature on pregnancy and birth complications and long‐term maternal mental health outcomes.Search strategySystematic search of Cumulative Index to Nursing and Allied Health Literature (CINAHL), Excerpta Medica Database (Embase), PsycInfo®, PubMed® and Web of Science from inception until August 2022.Selection criteriaThree reviewers independently reviewed titles, abstracts and full texts.Data collection and analysisTwo reviewers independently extracted data and appraised study quality. Random‐effects meta‐analyses were used to calculate pooled estimates. The Meta‐analyses of Observational Studies in Epidemiology (MOOSE) guidelines were followed. The protocol was prospectively registered on the International Prospective Register of Systematic Reviews (PROSPERO: CRD42022359017).Main resultsOf the 16 310 articles identified, 33 studies were included (3 973 631 participants). Termination of pregnancy was associated with depression (pooled adjusted odds ratio, aOR 1.49, 95% CI 1.20–1.83) and anxiety disorder (pooled aOR 1.43, 95% CI 1.20–1.71). Miscarriage was associated with depression (pooled aOR 1.97, 95% CI 1.38–2.82) and anxiety disorder (pooled aOR 1.24, 95% CI 1.11–1.39). Sensitivity analyses excluding early pregnancy loss and termination reported similar results. Preterm birth was associated with depression (pooled aOR 1.37, 95% CI 1.32–1.42), anxiety disorder (pooled aOR 0.97, 95% CI 0.41–2.27) and post‐traumatic stress disorder (PTSD) (pooled aOR 1.75, 95% CI 0.52–5.89). Caesarean section was not significantly associated with PTSD (pooled aOR 2.51, 95% CI 0.75–8.37). There were few studies on other mental disorders and therefore it was not possible to perform meta‐analyses.ConclusionsExposure to complications during pregnancy and birth increases the odds of long‐term depression, anxiety disorder and PTSD.