Introduction and hypothesis: We provide a review of the literature about the onset and development of hypertrophy of the labia minora, together with some expert opinions on the appropriateness of labiaplasty.
Methods: We searched PubMed and used popular search engines, with a greater emphasis on the physiology and hormone-mediated metabolism of these structures, and less emphasis on their surgical treatment.
Results: We describe major embryological, cytological, and biochemical features of this anatomical part and summarize the clinical aspects of its hypertrophy, evaluating types of discomfort reported by women and the medical treatments available. Also, based on what is known about the artificial elongation and spontaneous hypertrophy of the inner labia, we illustrate and discuss the main biological factors that may trigger this medical condition. There are not enough data identifying a clear inheritance of inner labia hypertrophy in the absence of other pathological conditions; instead, we found indirect evidence for an association with transient episodes of local inflammation either before birth or during puberty. We also analyze the role played by estrogen receptors and other factors with regard to the onset of this condition and highlight the importance of their timing in determining the size of women's labia minora. Remarkably, most cases of enlarged labia minora should be considered as outliers that are within the physiological range of size variation described for these structures.
Conclusions: We generally advise against surgical treatment of labia minora, especially in young, pre-pubertal girls, unless specific medical conditions are also present and/or the psychological impact on the patient is deemed particularly negative.
Keywords: Causes of labial hypertrophy; Inflammation; Labia minora manipulation; Labiaplasty; Psychological discomfort; Sexual hormones.