Abstract Background Identifying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections during peripartum hospitalizations is important to guide care, implement prevention measures, and understand infection burden. Methods This cross-sectional analysis used electronic health record data from hospitalizations during which pregnancies ended (peripartum hospitalizations) among a cohort of pregnant persons at 3 US integrated healthcare networks (sites 1–3). Maternal demographic, medical encounter, SARS-CoV-2 testing, and pregnancy and neonatal outcome information was extracted for persons with estimated delivery and pregnancy end dates during March 2020–February 2021 and ≥1 antenatal care record. Site-stratified multivariable logistic regression was used to identify factors associated with testing and compare pregnancy and neonatal outcomes among persons tested. Results Among 17 858 pregnant persons, 10 863 (60.8%) had peripartum SARS-CoV-2 testing; 222/10 683 (2.0%) had positive results. Testing prevalence varied by site and was lower during March–May 2020. Factors associated with higher peripartum SARS-CoV-2 testing odds were Asian race (adjusted odds ratio [aOR]: 1.36; 95% confidence interval [CI]: 1.03–1.79; referent: White) (site 1), Hispanic or Latino ethnicity (aOR: 1.33; 95% CI: 1.08–1.64) (site 2), peripartum Medicaid coverage (aOR: 1.33; 95% CI: 1.06–1.66) (site 1), and preterm hospitalization (aOR: 1.69; 95% CI: 1.19–2.39 [site 1]; aOR: 1.39; 95% CI: 1.03–1.88 [site 2]). Conclusions Findings highlight potential disparities in SARS-CoV-2 peripartum testing by demographic and pregnancy characteristics. Testing practice variations should be considered when interpreting studies relying on convenience samples of pregnant persons testing positive for SARS-CoV-2. Efforts to address testing differences between groups could improve equitable testing practices and care for pregnant persons with SARS-CoV-2 infections.