Development of vulva nomograms and assessment of female genital self-image: does the size of labia minora really matter?

Background: Labiaplasties have significantly increased, mainly because of aesthetic dissatisfaction, despite the lack of clear definitions for vulva dimensions.

Aim: To develop nomograms of the different vulvar structures and secondly to assess their association with women's genital self-perception in our setting (teaching hospital in Spain).

Methods: Prospective cross-sectional study including women >16 years old attending gynecological consults for non-aesthetic reasons without vulvar pathology. A sociodemographic survey, and the validated questionnaires Female Genital Self-image scale-Spanish (FGSIS-S) and Genital Appearance Satisfaction-Spanish (GAS-S) were administered prior to the measurement of the external genital structures (labia majora, labia minora, and clitoral hood) and assessment of phenotypical characteristics.

Outcomes: Participants were stratified into three age groups (<30, 30-49, $\ge$50 years) and the relationship between the widest labia minora and reported genital concern was analyzed using logistic regression; and its relationship with FGSIS-S and GAS-S scores through ordered logistic regression.

Results: 247 women aged 17-73 years old were included. Anatomy showed great variability. Vulva measurements (in mm) were (mean ± standard deviation): clitoral hood length 24 ± 9; and width 9 ± 3; labia minora width, right 19 ± 9, left 20 ± 8; and length, right 36 ± 13, left 41 ± 13. There was no significant association between the width of labia minora and the report of concern about genital appearance (P = 0.16), nor with FGSIS-S or GAS-S. We found a mild significant association between the length of the labia minora and women's report of concern (OR 1.02 (95% CI 1.00-1.04), P = 0.03); and with GAS-S (0.02 (95% CI 0.005-0.04)). After adjusting by age and parity, the length of the labia minora became non-statistically significant.

Clinical implications: These references can help healthcare professionals educate patients about vulvar phenotypical diversity and provide better counselling, but they should be used cautiously to avoid medical pathologization when anatomy is not within the range described in studies.

Strengths and limitations: We provide a comprehensive approach to self-perception of genital satisfaction including validated questionnaires and measurements of different structures. The main limitation is the relatively small sample size that did not allow for stratification into more age groups or ethnicity subclassification and a possible self-selection bias of women who attend gynecological consults.

Conclusion: Nearly half of the women in gynecological consults reported concern about genital appearance, unrelated to labia minora width or other measurements after adjusting by age and parity.