OBJECTIVE: This study aimed to systematically assess perinatal outcomes of pregnancies complicated by maternal cardiomyopathy. DATA SOURCES: PubMed, Ovid Embase, Ovid MEDLINE, the Cochrane Library, and ClinicalTrials.gov were systematically searched from inception to August 25, 2022. STUDY ELIGIBILITY CRITERIA: Observational cohort, case-control, and case-cohort studies in human populations were included if they reported predefined perinatal outcomes in pregnant women with cardiomyopathy (any subtype) and an appropriate control population (either pregnant women with no known cardiac disease or pregnant women with noncardiomyopathy cardiac disease). METHODS: Of note, 2 reviewers independently assessed the articles for eligibility and risk of bias, and conflicts were resolved by a third reviewer. Data were extracted and synthesized according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Meta-analysis of Observational Studies in Epidemiology guidelines. RESULTS: Here, 13 studies (representing 2,291,024 pregnancies) were eligible for inclusion. Perinatal death was more likely in neonates born to women with cardiomyopathy than in (1) neonates born to women with no cardiac disease (stillbirth: odds ratio, 20.82; 95% confidence interval, 6.68-64.95; I2 = not available; P<.00001; neonatal mortality: odds ratio, 6.75; 95% confidence interval, 3.54-12.89; I2=0%; P<.00001) and (2) neonates born to women with other forms of cardiac disease (stillbirth: odds ratio, 3.75; 95% confidence interval, 1.86-7.59; I2=0%; P=.0002; neonatal mortality: odds ratio, 2.42; 95% confidence interval, 1.39-4.21; I2=0%; P=.002). Pregnancies affected by maternal cardiomyopathy were significantly more likely to result in preterm birth (odds ratio, 2.21; 95% confidence interval, 1.31-3.73; I2=77%; P=.003) and small-for-gestational-age neonates (odds ratio, 2.97; 95% confidence interval, 2.38-3.70; I2=47%; P<.00001), both major causes of short- and long-term morbidities, than pregnancies affected by other forms of cardiac disease. CONCLUSION: There was an increased likelihood of adverse perinatal outcomes in pregnancies affected by maternal cardiomyopathy compared with both pregnancies affected by noncardiomyopathy cardiac disease and pregnancies without cardiac disease. Women with cardiomyopathy who plan to get pregnant should receive detailed counseling regarding these risks and have their pregnancies managed by experienced multidisciplinary teams that can provide close fetal monitoring and neonatology expertise.