Impact of obesity on surgical and patient-reported outcomes after masculinizing chest surgery: a systematic review and meta-analysis

Background Gender-affirming mastectomy improves body satisfaction and reduces gender dysphoria in transmasculine and non-binary individuals. Given the higher prevalence of obesity in this population, BMI-based surgical restrictions may have significant implications. However, evidence linking obesity to postoperative outcomes remains limited and heterogeneous.Methods We conducted a systematic review and meta-analysis of studies published up to January 2026 in PubMed, Embase, and Cochrane. Comparing outcomes in obese versus non-obese patients undergoing chest masculinization. Primary endpoint was overall complications; secondary included hematoma, seroma, surgical site infection, revision surgery, and patient-reported outcomes. Random-effects models calculated risk ratios (RR) with 95% confidence intervals (CI).Results Eleven studies with 12,220 patients were included. Obese patients had a higher risk of infection (RR 2.50, 95% CI 2.03–3.08, p < 0.01, I2 = 0%) and secondary revision (RR 1.71, 95% CI 0.77–3.8, p = 0.19, I2 = 49%). Subgroup analyses demonstrated a dose–response relationship, with higher infection rates in BMI 35.0–39.9 kg/m2 and ≥40.0 kg/m2. Wound dehiscence increased significantly only in BMI ≥40.0 kg/m2, while seroma risk remained non-significant.Conclusions Obesity may increase the risk of infection and wound complications at higher BMI levels. However, patient satisfaction and gender-affirming outcomes appear favorable.Registration PROSPERO: CRD420261297361