To evaluate nationwide adherence to surgical antibiotic prophylaxis (SAP) guidelines and its association with outcomes following gastrointestinal surgeries among neonates and infants.

We queried the National Surgical Quality Improvement Program-Pediatric for all patients age <90 days undergoing select thoracoabdominal surgical procedures between 2021 and 2023. Procedures were further subcategorized by anatomic site. SAP regimens were classified as being “adherent,” “undercoverage,” or “overcoverage” per established guidelines and expert consensus. The primary outcome was surgical site infection (SSI). Associations between SAP classification and SSI rates for each procedure subcategory were analyzed, with further subset analyses to delineate the effects of common SAP regimens on postoperative outcomes.

A total of 11 062 cases met criteria, with an overall SAP adherence of 87.2%. Rates of overcoverage (2.8%-55.5%) and undercoverage (2.8%-28.3%) varied widely by procedure type. SAP undercoverage did not increase the odds of SSI for most procedures analyzed, with the exception of patients undergoing colorectal procedures, in whom cefazolin monotherapy (undercoverage) was associated with higher odds of SSI (OR = 2.17, 95% CI = 1.08-4.18). Broadening SAP coverage (overcoverage) and prolonging SAP duration were not associated with reduced SSI rates for any subcategory of procedure.

Adherence to empiric SAP guidelines was poor among neonates and very young infants undergoing surgical intervention. There appears to be limited benefit to broadening SAP coverage for surgery in this patient population. These findings underscore the need for increased adherence to recommendations driven by neonatal-specific data, aiming to balance optimized postoperative outcomes with antimicrobial stewardship goals.