Abstract Background The relationship between body mass index (BMI) and postoperative morbidity in breast augmentation remains poorly defined. This gap limits evidence-based decision-making amid rising BMI trends. Our study aims to establish a BMI-based risk threshold and quantify its impact on 30-day morbidity following aesthetic breast augmentation. Methods We retrospectively analyzed the American College of Surgeons National Quality Improvement Program database (2009–2023). Adult female patients undergoing elective primary breast augmentation for aesthetic purposes were included. BMI cut point determination employed cubic spline modeling followed by Youden Index optimization. Propensity score matching and multivariable logistic regression were utilized to evaluate the association between BMI and 30-day postoperative outcomes. Results Among 6,515 patients analyzed, we identified BMI ≥25.2 kg/m 2 as a statistically derived risk threshold, with 21.0% (n=1,363) of patients exceeding this cut-point. Patients above this threshold demonstrated significantly higher baseline comorbidity burden, including hypertension (6.0% vs 2.3%, p < 0.001) and diabetes mellitus (2.2% vs 0.5%, p < 0.001). Overall 30-day morbidity was markedly elevated in the higher BMI cohort (4.3% vs 1.3%, p < 0.001), with corresponding increases in reoperation rates (1.9% vs 0.8%, p = 0.014) and unplanned readmissions (1.1% vs 0.2%, p < 0.001). Multivariable analysis confirmed BMI ≥ 25.2 kg/m 2 as an independent predictor of adverse outcomes (adjusted OR 3.13, p < 0.001). Propensity score matching validated this association with similar effect magnitude (OR 3.35, p < 0.001). Conclusion This analysis establishes BMI ≥25.2 kg/m 2 as a clinically actionable threshold associated with a more than threefold increase in perioperative complications following aesthetic breast augmentation. These findings provide an evidence-based foundation for BMI-stratified risk assessment and informed consent protocols in breast augmentation. Implementation of enhanced perioperative surveillance and risk mitigation strategies should be considered for patients exceeding this threshold to optimize surgical outcomes and patient safety. Level of Evidence III This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
Knoedler et al. (Wed,) studied this question.