Aug 15

Labia minora: anatomy and sex

Labiaplasty, cosmetic gynecologic surgery, female sexual function and anatomy of the female vulva

Vulvar anatomy circa 1798. Some things never change. Thank goodness...


Every two months I report for on scientific manuscripts in the recent medical literature for the Journal of Sexual Medicine that pertain to female sexual function. In an anatomic study of vulvar anatomy published in the journal of the American Urogynecologic Society, scientists took a close look at the microscopic goings on of labia minora. The controversy over labiaplasty and other forms of cosmetic gynecologic surgery rages on, with proponents on both sides claiming “fair” and “foul” in equal measure.

The clitoris has erectile function

Unless you believe in the G-Spot orgasm and are of the opinion that there is a difference between “internal/vaginal” and “external/clitoral” orgasms for women, you’re probably in agreement with most physiologists and anatomists that the female orgasm emanates from the clitoris, the organ in the body with the highest density of sensory nerves and an intense erectile response to sexual stimulation. That’s right, ladies. Your clitoris gets a woody every time you have an orgasm, or even get aroused.  The role of labia majora and labia minora in this erectile and orgasmic function is so poorly understood it’s almost criminal. Seriously – do you know how much is understood about male sexual function and role of erectile tissue in a man’s sexual pleasure? They’ve written books about it. An entire pharmaceutical industry is making $$bajillions catering to it. Courses are taught, books are written, Medicare PAYS FOR IT (all of it) right down to the fancy shmancy-est of prosthetic penile implants.

Labia minora: high density of nerve function and blood flow

So this study took a look at the micro-anatomy of labia minora. Few studies have reported any meaningful data on labiaplasty’s (surgical reduction of labia minora) impact on sexual function. There is one study by a renowned cosmetic genital surgeon who reported that out of 166 women undergoing combined labiaplasty and clitoral hood reduction, 38 reported better sexual pleasure and 9 reported a worse, or a negative impact on sexual function, from the procedure. This raises the question that it may be possible for genital cosmetic operations done to improve sexual function may actually have the opposite effect…

Being that the subjects in this particular study were all cadavers, evaluating sexual function was not possible. But the researchers did find a high density of nerve fibers on both the outer and inner surfaces of labia minora in all specimens, in addition to a high density of blood vessels, in excess of that needed to maintain the skin of the labia, indicating a high likelihood that the blood vessels of the labia minora play some role in the sexual response and possibly in the engorgement and erectile function of the clitoris, although these points remain to be proved in studies on live women.

Remember, one study does not an absolute fact make. This area of gynecologic surgery is in evolution, and this anatomy study is one important contribution to that body of literature that will permit, over time, for meaningful conclusions to be made.

Here’s the summary to appear in the Journal of Sexual Medicine sometime this fall:

Ginger VAT, Cold CJ, Yang CC.

Structure and innervation of the labia minora: more than minor skin folds.

2011 Female Pelvic Medicine & Reconstructive Surgery  17:4, 180-3.

Eight fresh cadaveric vulvar specimens were fixed and stained to report the histologic features of the labia minora with regard to female sexual function.

Labia were highly variable in appearance. Labia minora were thin in relation to majora, and in some cases fused. No labia minora contained fatty component, as do the labia majora. After fixation and histologic staining, the inner labum minus were found to be  covered by a basket-weave keratin type dermis.. The substance included numerous vascular structures surrounded by connective collagen and no smooth muscle, thereby making the labia minora vascular tissue non-erectile.  Elastin was abundant, as were neural elements with no difference in distribution of neural elements between the lateral and medial sides of the labia minora. There was a central core of neural elements long the length of the labia, traveling alongside vascular structures to form the neuro-anatomic substrate where sexual arousal results in labial engorgement. Neural elements were sparse with in the labia majora.  Histologic images are included to illustrate these findings. The authors go on to comment on genital labioplasty done for aesthetic or functional reasons, reiterating that reports of diminished sexual responsiveness are documented in at least one series of 166 women undergoing labiaplasty and clitoral hood reduction, where 9 reported negative effect on sexual sensation in contrast to 38 reporting improved sexual sensations.  They note that among reports on labia minora structure, very little mention is made of possible function. They comment that the specimens obtained for hits study were likely, but not know for certain, to be from menopausal women in which degenerative changes would have been present and that despite this, a high density of neural and vascular elements were found in the labia minora of the specimens evaluated.  They finish by stating that “Biochemical and molecular studies may further elucidate (the labia minora’s) role in the female sexual response,… which are specialized vascular structures with densely distributed neural elements providing anatomic substrate for changes observed during sexual arousal”.

Content herein does not represent medical advice. To learn more about pelvic floor disorders such as fistula, pelvic organ prolapse, dropped bladder, dropped uterus, hysteropexy uterine resuspension, vaginal laxity, rectocele, postpartum rehabilitation, vaginal rejuvenation, labiaplasty, vaginoplasty, Kegel exercise or incontinence please visit other posts in this blog and the Urogynics website at www.urogynics.org.

1 comment

  1. David Mills

    Superb article , congratulations.
    We are finding that labia reduction is becoming increasingly popular with more and more enquiries being received for this procedure in the United Kingdom.
    Many women specifically request local anaesthesia for the procedure in our experience

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