OBJECTIVE: To compare frequencies of risk factors and pregnancy outcomes in ethnic groups versus the combined total of Asian American, Native Hawaiian, and Pacific Islander (AANHPI) populations. METHODS: Using linked birth and fetal death certificate and maternal hospital discharge data (California 2007-2018), we estimated frequencies of 15 clinical and sociodemographic exposures and 11 pregnancy outcomes. Variability across 15 AANHPI groups was compared using a heat map and compared to frequencies for the total group (n = 904,232). RESULTS: AANHPI groups varied significantly from each other and the combined total regarding indicators of social disadvantage (e.g., range for high school-level educational or less: 6.4% Korean-55.8% Samoan) and sociodemographic factors (e.g., maternal age <20 years: 0.2% Chinese-8.8% Guamanian) that are related to adverse pregnancy outcomes. Perinatal outcomes varied significantly (e.g., severe maternal morbidity: 1.2% Korean-1.9% Filipino). No single group consistently had risk factors or outcome prevalence at the extremes, i.e., no group was consistently better or worse off across examined factors. CONCLUSIONS: Substantial variability in perinatal risk factors and outcomes exists across AANHPI groups. Aggregation into AANHPI is not appropriate for outcome reporting.