From universal provision to equitable access: city-level linguistic diversity and access to maternal and child health education among migrant mothers in China

Migration changes not only where mothers live, but also the linguistic and institutional environments through which they encounter health information, primary public health systems, and community support. Existing research has largely explained disparities in maternal and child health services among migrants in terms of individual language proficiency or specific patient–provider communication encounters, while paying less attention to whether the overall linguistic structure of destination cities is associated with actual receipt of preventive services. This study conceptualizes city-level linguistic diversity as a contextual exposure reflecting urban linguistic structure, evaluates its association with receipt of maternal and child health education (MCHE) among migrant mothers in China, examines whether this association varies by the age of the youngest child and cross-dialect migration, and assesses explanatory pathways related to awareness of public health services, contact with the health system, and psychosocial integration. We linked the China Migrants Dynamic Survey with data on urban linguistic environments and city-level socioeconomic characteristics. The analytical sample comprised female migrants aged 15–49 years who had lived in the destination for more than six months and had at least one child aged 0–6 years, yielding 26,170 respondents across 333 cities. The outcome was receipt of MCHE, and the primary exposure was the city-level linguistic diversity index (LDI). Baseline analyses used linear probability models adjusting for individual- and city-level characteristics and province fixed effects, with standard errors clustered at the city level. Robustness was assessed using entropy balancing, Oster sensitivity analysis, city-level permutation tests, alternative models and linguistic measures, restricted samples, adjustment for city administrative status, and Conley-type spatial heteroskedasticity and autocorrelation consistent (HAC) standard errors. Association heterogeneity was examined using interactions with the age of the youngest child and cross-dialect migration, with multiple-testing adjustment using the Benjamini–Hochberg false discovery rate (FDR) procedure. Karlson–Holm–Breen (KHB) decomposition was used to assess the statistical contribution of four explanatory pathways to the observed association. In the fully adjusted model, higher LDI was associated with a lower probability of MCHE receipt (β=−0.1014, SE = 0.0329, p < 0.01). A one-standard-deviation increase in LDI corresponded to an average 2.12-percentage-point lower probability of MCHE receipt, and the result was consistent across multiple sensitivity and robustness analyses. Association heterogeneity analyses showed that the negative association weakened as the age of the youngest child increased (interaction β = 0.0164, FDR-adjusted q = 0.0509) and was more pronounced among mothers who had migrated across dialect regions (interaction β = 0.1063, FDR-adjusted q = 0.0363). KHB decomposition indicated that awareness of Basic Public Health Services and having a local resident health record explained 20.97% and 19.46% of the total association, respectively, whereas willingness to integrate and affective identification with the city accounted for smaller proportions. Destination-city linguistic diversity showed a stable contextual association with a lower probability of MCHE receipt among migrant mothers in China. This association was more pronounced among mothers whose migration crossed dialect-region boundaries and may weaken as the age of the youngest child increases. In efforts to advance equitable access to Basic Public Health Services, health service managers may consider the comprehensibility of information, modes of service communication, and the actual language needs of different migrant groups in cities with more diverse linguistic structures.