Systematic Review and Meta-Analysis of Labia Minora Anatomy in Premenopausal Women: Toward Better Labiaplasty...

Background: The labia minora are cutaneous folds richly innervated along their entire edge and are important for the protection of internal structures. Several studies have emphasized the wide interindividual variability in labia minora appearance. Aim: We aimed to conduct a systematic review and meta-analysis of research that has quantitatively described labia minora in healthy premenopausal adult women. Methods: Following Joanna Briggs Institute (JBI) and Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 (PRISMA 2020) guidelines, we searched PubMed, Scopus, and Web of Science without date or language restrictions using the following terms and Boolean operators: ("labia minora" OR "vulva") AND (anatom*) AND (measure* OR morphometr*). The search was last conducted on 27 October 2025. Observational studies reporting clinical measurements of labia minora length and/or width in women undergoing routine gynecological care were included. Results: The total number of records identified was 567. Seven cross-sectional studies comprising 991 women met the inclusion criteria. All studies collected measurements in hospital or outpatient clinical settings in Europe, Asia and the Middle East. All the measurements were conducted in the lithotomy position using standardized instruments. The range of labia minora length across studies varied from 36.5 mm to 60.6 mm. The labia minora width ranged from 14.7 mm to 21.8 mm. All studies described marked interindividual variability, with wide, overlapping ranges between samples. An important limitation concerns the incomplete assessment of measurement reliability in two of the included studies. A total of three studies, encompassing 307 women, provided the necessary data to permit meta-analysis. The pooled mean labia minora length was 53.23 mm (95% CI: 43.50-62.96), while the pooled mean labia minora width was 18.28 mm (95% CI: 14.93-21.64). The analysis of between-study variability revealed statistically significant heterogeneity (Cochran's Q test, p < 0.001) and considerable heterogeneity (I² > 75%) for both outcomes, i.e., labia minora length and width. Conclusions: The findings demonstrate substantial variability in labia minora dimensions. The integration of these data into medical education and clinical guidelines may be useful to reduce unnecessary interventions. Register: PROSPERO (registration number: CRD420251174590).