Diffusion and division: A spatial analysis of surrogacy policy determinants in the United States

Advancements in reproductive technologies have made surrogacy an increasingly attractive option for individuals and couples facing fertility challenges. In 2022, the global commercial surrogacy market was valued at approximately $14 billion, with the United States contributing a significant share due to its robust healthcare and legal infrastructure. However, surrogacy policy in the United States remains highly fragmented-some states have permissive legal frameworks, others prohibit surrogacy entirely, and many have no formal statutes. This study examines how states' political ideology, religiosity, and socioeconomic factors influence the adoption of surrogacy policies across the United States.

We conducted a spatial analysis using data from the United States Census Bureau, World Population Review, and the United States Surrogacy Law Map. States were categorized based on the permissiveness of their surrogacy policies. Spatial lag regression model and ordered logistic regression models were employed to assess associations between policy status and independent variables, including religiosity, political affiliation, income, and racial demographics.

Moran's I indicated significant positive spatial clustering of surrogacy law permissiveness across states (I = 0.206, p < 0.05), suggesting geographic diffusion of policy environments. Spatial lag regression results showed that higher religiosity was associated with more restrictive policies, although this effect attenuated after adjusting for socioeconomic and political factors. Ordered logistic regression models confirmed these associations while explicitly accounting for the ordinal outcome structure: higher religiosity significantly decreased the odds of permissive policies (Model 1: β = -0.124, p < 0.05), whereas racial diversity predicted greater policy permissiveness. In fully adjusted models, the percentage of White, Black, and Hispanic residents remained positive and significant predictors of permissive surrogacy laws, while religiosity trended negative but fell just short of statistical significance (p = 0.07).

This study demonstrates that a combination of religiosity, racial composition, and spatial proximity to like-minded states shapes state-level surrogacy policy in the United States. Higher religious adherence is linked to more restrictive policies, while a greater proportion of White residents correlates with increased permissiveness when broader structural factors are considered. The findings underscore the importance of accounting for sociopolitical and geographic context in reproductive policy analysis. To promote equitable access to assisted reproductive technologies, public health efforts and legal reforms must consider these underlying sociocultural and spatial dynamics.