Disentangling feeding practices from socioeconomic risk factors in pyloric stenosis risk

Formula feeding, tobacco use, and family history have been well-established as risk factors for hypertrophic pyloric stenosis (HPS). Several markers of socioeconomic status have also been associated with HPS, however, their relationship to other risk factors has not been delineated. The purpose of this study is to investigate the relationship between socioeconomic factors and known risk factors for HPS.

We identified 735 patients who underwent pyloromyotomy at a high-volume children's hospital between 2012 and 2025. These patients were matched one-to-one by sex, gestational age, age, race, and ethnicity with 735 controls from the general pediatrics clinic at the same institution. A case-wise deletion was performed to address data missingness, which resulted in a final cohort of 725 controls and 655 cases. Data was retrospectively collected from patient charts and analyzed.

Univariate logistic regressions revealed formula feeding, maternal tobacco use, family history of HPS, and public medical insurance were associated with HPS while very high Child Opportunity Index (COI) score was associated with a lower risk of HPS. On multivariable analysis, formula feeding, maternal tobacco use, and family history remained significant, however, public insurance and very high COI were no longer significant. COI and feeding type were significantly correlated on Chi-square analysis.

Socioeconomic factors are associated with HPS on unadjusted analysis, however, they are not independent predictors. This is likely mediated by infant feeding practices, where formula feeding continues to be a primary driver of risk.