The nerves and vasculature of the clitoris are absent from OB/GYN literature.

Jessica Pin
Mar 23, 2018 · 12 min read

For clarification, I am refering to nerves and vasculature in the clitoris, not just leading up to it. My goal is to leverage social media support (so please clap and share) in order to get this anatomy added to OB/GYN textbooks and board exams, as direct appeals have not worked. The effect of this change would be improving female sexual medicine and protecting patients from preventable harm caused by surgeons’ ignorance of this anatomy.

The neurovascular anatomy of the clitoris has been published (as early as 1844). It also only takes scissors and a cadaver to know, as the nerves especially are quite large (please scroll to bottom for results of 12 dissections I’ve participated in). This omission appears to be caused by sociocultural discomfort with the clitoris and a pervasive lack of regard for female sexual response (seen as a bonus rather than necessity), as it is not legitimized by direct reproductive function.

Like the penis, the clitoris has a head (the tip you can see), also called the glans, which is the most sensitive part. In both the penis and clitoris, two main nerves lead up to the glans. These nerves are called the “dorsal nerves” and are quite large, as they supply the glans with thousands of nerve endings. That is why both the glans of the penis and glans of the clitoris are so sensitive. In both the penis and clitoris, the dorsal nerves travel along the top (dorsum) of the body (shaft) until they reach the glans. Their course along the body is important, because if injury happens here, that means altered or lost sensation in the glans.

The course of the dorsal nerves in the clitoris is highlighted in blue below. While it is shown minimally (and slightly incorrectly) in this illustration from an anatomy textbook (Netter), this detail is almost never found in OB/GYN literature, upon which OB/GYNs rely. The blood vessels also are not shown.

Though some OB/GYNs may know this anatomy, its omission from OB/GYN literature indicates a gap in education. Modern OB/GYN textbooks typically only show the course of nerves and vessels leading up to the clitoris. The nerves (large, not difficult to dissect) and vasculature in the clitoris itself are omitted. Here is a screenshot of the extent of vulvar anatomy covered in the most popular gynecologic surgery textbook (Te Linde’s Operative Gynecology):

The nerves and vasculature of the clitoris are missing from every single OB/GYN textbook (with the exception of Williams, only as of 2016) on this list of Residency and Board Review Best Books: Obstetrics and Gynecology. They are also missing from every textbook on this list, which includes several more. In fact, if anyone can find them shown and described in a textbook on this list, I will pay them $10,000.

The distal course (in the clitoris) of the dorsal nerves is also absent from all OB/GYN journal articles, except one article in a low impact factor journal (58th most cited) where the anatomy is incorrect — the glans is described as 1–2 cm long. As any owner of a clitoris or user of Google can readily discern, the glans is usually under 1 cm in length.

The nerves and vasculature of the clitoris are actually somewhat covered in Netter’s Atlas of Human Anatomy, Grant’s Dissector, and some other general anatomy textbooks. However, the omission from OB/GYN textbooks and journals (where surgeries are described with inadequate consideration of surgical anatomy involved) is still a problem, as it indicates it is getting forgotten. In fact, one OB/GYN on Quora explains how OB/GYNs rely on the content of their specialty’s literature:

“An obstetrician gynecologist would not rely on this atlas [Netter] for their pelvic anatomy. When we choose to specialize, we end up with stacks of other textbooks and surgical atlases more consistent with our specialty.” — Dr. Lacy Windham (perfect example of an OB/GYN who can’t recognize where the neural anatomy of the clitoris is missing)

Normally, coverage of specialty-relevant anatomy increases as you move into the literature for that specialty, but in OB/GYN literature, previously covered vulvar anatomy disappears. Even just coverage at this level (Netter) would be a vast improvement (though this is actually not correct):

Here is an explanation of the problem, which I received from a urologist who has done significant research (perhaps the most of anyone in the US) on vulvar anatomy (including neurovasculature of clitoris):

Jessica:

OB/GYN ignorance of operative vulvar anatomy is dangerous because they put this anatomy at risk in a number of procedures. It should be known for understanding and treatment of sexual dysfunction, repairs of injuries, surgical treatment of vulvar cancer, and vulvar cosmetic surgeries (“treatment of hypertrophy” where “hypertrophy” is defined in the literature as less than the mean), which according to one survey study, 77% of GYNs offer to patients.

It is notable that detailed illustrations of clitoral neurovascular anatomy were published by Kobelt in 1844. They are still arguably the best, most detailed illustrations to date, though from looking at cadaver dissections and in my own dissections so far, the dorsal nerves can be bigger relative to the size of the body and they do not usually branch like this. Almost no modern illustrations have even attempted to show the course of nerves and vasculature close up or from multiple angles.

These began to circulate in 19th century gynecology textbooks. However, within a few years, many English physicians would begin to claim the clitoris was useless and should be excised as a cure for hysteria. In 1884, it was established that the clitoris played no role in conception, reducing it’s perceived medical relevance. The final blow was dealt by Freud, who insisted that normal adult orgasms are vaginal.

Imagine a world where penile neurovascular anatomy is ignored in textbooks, and where urologists do surgeries without ever learning the nerves and vasculature of the penis. It should not be difficult to see there is a problem.

This is a problem I’ve been trying to figure out how to change for years. Unfortunately, it is very difficult due to OB/GYN reticence to acknowledge what they don’t know. Even when they do acknowledge it, it is difficult to get past justifications that it is not important. Even one OB/GYN friend of a friend was resistant, opining that she doesn’t think this anatomy should be on board exams because she already has to know so much.

I’ve tried a lot of different strategies with very little success. I tried emailing the executive director, president, and several other directors at ABOG, the American Board of OB/GYN. Based on their emails to me, none were amenable to adding clitoral neural anatomy (in the clitoris itself) to their board exams. Adding it to board exams seems like the most efficient solution, as OB/GYNs will make sure they know what is on their boards. This small change would change education nationally. If I could get enough OB/GYNs to support and request this change, I believe they would consider it.

I have emailed over 15 residency programs. Most residency directors ignore me. One called legal to make sure they couldn’t get sued for not teaching it. ACOG, the American College of OB/GYNs, refuses to acknowledge a problem, though they allegedly are considering correcting factual errors in their committee opinions. ACGME , the Accreditation Council for Graduate Medical Education, has insisted there is no problem.

It is notable that, as of March 2018, the only vulvar surgery listed in the ACGME application for accreditation is “radical vulvectomy,” which is a surgery for vulvar cancer. Because the goal is to remove the cancer, detailed anatomy and function are not taken into account (though they perhaps should be). But according to USPI, the biggest ambulatory care provider in the U.S., ABOG and ACGME assure them OB/GYNs are qualified to do vulvar cosmetic procedures.

I tried crashing the ACOG convention with flyers showing the anatomy missing from their textbooks, and asking for help changing this. While some OB/GYNs seemed receptive, not a single OB/GYN contacted me to help. I’ve also emailed over 100 OB/GYNs and tried appealing to them via Twitter. Only two retweeted me. If any OB/GYNs are reading this, I would really appreciate help and advice about how to overcome this resistance.

I previously wrote a ~200 page research paper trying to show systemic negligence in GYN regarding female sexual function and vulvar anatomy across the board by analyzing the literature, ACOG committee opinions, etc. It got way too broad, overwhelming, and depressing. 200 pages got me half way through my outline. I could never finish it. I think if I can at least change OB/GYN education in clitoral anatomy, this will be enough for me to move on, knowing I have made a difference. I think if I can get regular people to care about this gap in education, I can change it.

The best coverage of clitoral neurovascular anatomy is in Anatomic Study of the Clitoris and Bulbo-Clitoral Organ, by Di Marino and Lepidi. They describe the anatomy in great detail and display over 100 photos of cadaver dissections, like these:

These photos show a view of each dorsal nerve from the side (labeled with 1, 2, and 3 to show the different segments). Here they appear at the 9 and 3 o’clock positions along the clitoral body, but this varies, with the nerves traveling more dorsally than laterally in some women. The nerves are about 2–4 mm in diameter as they enter the clitoral body and travel about 3 cm along the clitoral body before terminating in the glans — 3 cm past where they are shown to terminate in textbooks. While side views and cross sections in multiple planes are commonly shown for the penis, even on walls at clinics, detailed clitoral anatomy is consistently missing.

At the time I orginally posted this article on Medium in March, Di Marino and Lepidi’s work, though published in 2014, had never been cited in any medical journal articles published in English. Since then, it has been cited twice.

They also go over the history of its absence from medical literature and the continued gap in education. It would be really great if an artist was interested in making updated drawings (or a 3d image would be best!) based on these photos and MRI studies (for general morphology because cadavers have often atrophied). Contact me if you want to read it but don’t have access.

As I have gotten approval to participate in a study and have been asked to write a review for Sexual Medicine Reviews, I will likely post more when I’m done. It is difficult to figure out what I can do. Post in the comments if you have any ideas about how to spread awareness and get through to medical leadership.

Update (May 10, 2019):

I have now dissected and participated in dissections of 12 clitorises. In all 12, the two dorsal nerves were large and easily identifiable in the clitoral body. The defenses that they are too small or too difficult to dissect are even more absurd now that I’ve done it myself.

Based on measurements taken from 10 specimens, the dorsal nerves are 3.2 mm in diameter at the angle, on average. The angle is where the clitoral body body forms an acute angle and is where it attaches to the pubic bone. As the nerves travel along the surface of the clitoral body, for over 3 cm, they decrease in diameter, indicating that a large volume of branches are innervating the body and/or clitoral hood.

Here is a cross section at the angle, which I made into a cartoon so it’s not too gross-looking to laypeople.

You can see the ligament at the top in the middle, and you can see each nerve on the side of it. The one on the left side of the photo especially is hanging out a bit. My memory is that this one measured 16 mm across. But my measurements got thrown away.

The dorsal nerves of the clitoris are 2.0 mm in diameter, on average, at or near the glans of the clitoris, at the terminal point where they begin branching too much to continue dissecting. In 4 out of 10 specimens dissected and measured as part of an official study, nerves of around 2.1 mm in diameter, on average, were seen inserting directly into the glans of the clitoris.

Here are the nerves, dissected off of the body, leading up to the glans. I made it a cartoon so it wouldn’t gross anyone out. Keep in mind that OB/GYN textbooks show these nerves terminating at or prior to the 1 cm mark on the ruler. This is wrong.

Getting an illustrator to illustrate this anatomy accurately is what is holding up publication. She keeps referring to existing textbook illustrations, and I keep trying to correct her. It’s incredibly frustrating. In the meantime, I drew this for her. This is different from Netter, as the clitoral body extends internally beyond the top of the clitoral hood.

One unexpected result is that our clitorises were much larger than indicated in OB/GYN textbooks. Based on measurements taken with a caliper by a plastic surgery resident, the length from the point where the suspensory ligament attaches to the angle and the base of the glans was 37.0 mm, based on the last 5 specimens (I had to fight to get this measured). The length from the top of the clitoral hood to the tip of the glans was 23.4 mm, based on the last 5 specimens. The average glans length, surprisingly, was 7.9 mm. The diameter of the clitoral body, measured at the point where the dorsal nerves could no longer be dissected further (at the glans in 4 specimens) was 7.1 mm.

Although, extra diameter measurements I took of the clitoral body (it is neither consistently cylindrical nor constant in diameter along it’s length) sadly got thrown away, there are photos of cross sections clearly showing the clitoral body at various points along its length is over 10 mm across — much wider than people typically think. My memory is this one was taken about halfway to the glans. As you can see, it is composed of two corpora, just like the penis. Unlike the penis, there is no visible spongiosum. Illustrations of cross-sections of the clitoris should also be shown in medical textbooks. They are always shown for the penis.

There has also been a hold up due to the illustrator’s confusion regarding how to represent the anatomy of the suspensory ligament of the clitoris. This was of interest to my father and the plastic surgery residents, so it was measured as well.

Claps are greatly appreciated. If you hold down the clap icon, you can clap up to 50.

Jessica Pin

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Trying to get clitoral neural anatomy included in OB/GYN textbooks. Much more active on Quora. BME/EE @WUSTL