Thicker Urethrovaginal Space = Vaginal Orgasm?: A Journal Article I Read

Here's the new "A Journal Article I Read". I think this is a useful and interesting paper that is well worth doing follow-up studies on. However, if you were hoping to find evidence that vaginal orgasms exist, this is not the paper. It assumes they exist, and assumes the women that claim to orgasm vaginally in the study are all describing a physically definable event, but in the end this study neither is able to define/describe a mechanism for vaginal orgasm nor is it able to give indication whether they exist at all. It does, however, show a physiological difference between  9 women who claim to orgasm vaginally and 11 women who claim to not orgasm vaginally, and that's intriguing.

"Measurement of the thickness of the urethrovaginal space in women with or without vaginal orgasm." Gravina GL, Brandetti F, Martini P, Carosa E, Di Stasi SM, Morano S, Lenzi A, Jannini EA. J Sex Med. 2008 Mar;5(3):610-8.

The background of this article basically discusses how there is debate about whether the vagina is sensitive  and/or related to orgasm and that there is some indication that the area around the anterior wall of the vagina and the urethra and bladder area differ among women and may be related to sexual function. It's pretty normal stuff for this kind of article, but I'm gonna be a bit picky here and tell you this following statement in this article is annoying to me.
"it is evident that some women need direct, external clitoral stimulation whereas others may reach orgasm also by penetration and thrusting that directly stimulate the internal clitoris and vaginal wall structures."
The thing is, it is evident that women can orgasm through direct clitoral stimulation. There's tons of direct physical data to prove that. There, however, is no direct physical data at all showing a connection between penetration/thrusting and an orgasm. It simply doesn't exist, and making statements like that just create a false sense of scientific certainty to go with already existing false cultural certainty.   It should say:
"it is it is evident that some women need direct, external clitoral stimulation, and it is assumed that others may reach orgasm also by penetration and thrusting that directly stimulate the internal clitoris and vaginal wall structures."
Okay - so that done - here is how they describe their aim with this study.
"Differences in women's sexual function obviously exist and although they have been largely attributed to cultural, religious, intrapsychic and, above all, relational factors [21], it is possible that anatomical factors might be partly responsible. Thus, if "anatomy is destiny" [22], physical differences should be taken into account as a source of physiological variability in female sexual response. With these concepts in mind, the purpose of this study was to use introital ultrasonography to evaluate anatomical variability, measured as the difference in thickness of the urethrovaginal space and to correlate this variability with the presence [of] vaginally activated orgasm."
37 volunteers were recruited from the normal controls of a previous study. The women were physically examined and deemed healthy in the genital regions. None had a history of "drug or alcohol abuse, medications or medical conditions which might alter sexual function, previous anti-incontinence surgery, or any stage of vaginal prolapse." None were considered to have sexual function problems. This meant to this study a total female sexual function index (FSFI) of over 26.55, and specifically only women with high scores for the following questions were included. (The authors note that these questions do not distinguish between clitoral and vaginal orgasm.)

Q.11 (how often did you reach orgasm) 
Q.12 (how difficult was it for you to reach orgasm), 
Q.13 (how satisfied were you with your ability to reach orgasm).

All participants were exclusively hetero, had stable relationships, and reported at least 2 acts of sexual intercourse per week, a regular menstrual cycle and had been sexually active in the past 6 months. All subjects were tested for this study at the same time in their menstrual cycle.

The male researcher then collected sexual histories in a separate setting and found out who said she could and who said she could not orgasm vaginally using the following question, "Have you ever experienced vaginal orgasm?"
"Responses were categorized as 'yes'(at least once in the past month) or 'no' (never). By vaginal orgasm we mean the orgasm experienced after direct stimulation of the anterior vaginal wall by penetration, without concomitant stimulation of the external clitoris."
 The other investigators didn't know which said they could and could not.

After all the tests, 6 participants were excluded because of sexual dysfunction, 7 because of menopause with or without sexual dysfunction, and 4 declined to participate, leaving 20 final participants. Of the 20, 9 reported experiencing vaginal orgasm.

The Urodynamic Assessment
The patients first went through a series of urodynamic assessments. It involved the testing of the rate at which the bladder empties and fills, the volume of the liquid in the bladder, and it uses electrodes at the "3 and 9 o'clock position" of the anal skin to record pelvic floor muscle activity during voiding. A catheter is involved.

The Ultrasound
Ultrasonography was performed using a transvaginal probe, but it was used outside the body.
"The ultrasound evaluation was obtained by an introital approach with the transducer placed over the external urethral orfice and the transducer axis corresponding to the body axis. Care was taken not to distort the anatomy during the procedure."  
The women were in a modified Trendelemburg position with a bladder filled to 300mL. I honestly am not completely sure if the probe was placed more vertical, sorta between the legs along the vulva or more horizontal, sorta parallel to the body but against the ol' pee hole. I'm assuming it's the former because, but I'm not sure. Maybe this would be more obvious to someone who does ultrasounds. Anyway, one female investigator, who did not know which women said they orgasmed vaginally and which didn't, performed all the ultrasounds, and they were recorded in both video and picture.

"Total urethral length and vaginal lumen were viewed in the midsagittal plane. The images was then frozen and filed digitally. Two blinded male investigators (G.L.G and P.M.) interpreted and measured the thickness of the urethrovaginal space from the ultrasounds in random order." 
So, first, vaginal lumen means the inside space of the vagina. Second, sagittal plane is pictured below, and third, the two researchers didn't know who said they could orgasm vaginally, so they couldn't be biased in that way. The thickness of the urethrovaginal space was measured 3 times each at 3 different places along the urethra and "the median value was considered for statistical purposes."

Statistical Analysis
There is a description of all the types of statistical analysis that was performed, and I'm just going to take their word that these make sense for their investigation because that is not my area of expertise, but please feel free to check out the article if you're interested.

I am also not familiar with how one would measure body parts through ultrasound, but again, I'm taking their word that the way they measured and the things they were measuring make sense with what they were trying to find.
"No significant difference was noted in age, parity, hormonal pattern, menstrual cycle duration, or FSFI total score among women with and without vaginal orgasm." 

They all also had normal results with the urodynamic assessment. Here's some of the ultrasound details:
"Figure 1 (panels A and B) shows the schematic representation and introital ultrasound image of the urogenital organs. The vagina is seen as a hypoanechoic strip, adjacent to the posterior wall of the urethra for a short distance, and running from the probe to the cervix fornix. The symphysis pubis appears as a hyperechoic shell, with a shaded cone. The rectum generates acoustic artifacts with loss of borders between the rectal and posterior vaginal wall. The urethral lumen was seen as an anechoic cylindrical structure. The striated and smooth muscle layers of the urethra cannot always be distinguished in the midsagittal plane. The mucosa and submucosa were uniformly depicted as hypo echoic structures mimicking an open lumen."

The urethrovaginal space was thicker at all 3 points for women who claim to have vaginal orgasms. There is actually no crossover in the data. All the non-vaginal orgasming women had thinner urethrovaginal space than all the women who said they could orgasm vaginally. So, these are good, interesting results, which should lead to more studies.

I think the authors were quite realistic about what this study does and does not say, and that is not something I always see, so I have a lot of respect for that. They went over, as you might expect, questions, future projects and the study's limitations.
"These results raise several questions. What anatomical structures did we measure? Does urethrovaginal space thickness differ in all women with vaginal orgasm, or have we identified as subset of patients? Have we measured the controversial G-spot in vivo?"
The authors  tell us that further, larger studies are "needed to confirm the possible correlation between the anatomy of the anterior vaginal wall and vaginal orgasm," and go on to say that they are currently working on urethrovaginal space studies with women that have changing or different levels of androgen.

They also go over the major limitations to this study. They tell us that ultrasonography is widely used, but
"its spatial and structural resolution remains lower than other imaging techniques. Consequently, the anatomical structures within the urethrovaginal space cannot be fully resolved by ultrasonography." 
Thus if there are other structure that are important in this area, this method would likely not find it. They point out that the sample size is quite small and that their data,
"should be considered preliminary and interpreted cautiously, given the small sample size. Additionally, accurate placement of the measuring cursor was more difficult when structural borders were indistinct, even if interobserver agreement was excellent." 
Also, and you know I think think this is important and waaay too often disregarded, so I truly appreciate that the authors recognized this,
"The self-reported nature of presence or absence of vaginal orgasm is another strong limitation of our findings. Formal demonstration of the orgasm is theoretically possible, but the majority of studies on the topic are based on the administration of inventories and questionnaires." 
And here are the authors' final words:
"The most interesting finding of our study is that women who experience vaginal orgasm have a urethrovaginal space thicker than those who do not. However, our data cannot directly demonstrate that the thickness of an anatomical "space" may generate a mechanism that can be related to the creation of an orgasm. But, in conclusion, the results here presented allow us to speculate that there may be a functional correlation between the thickness of urethrovaginal space, or G-spot, and the ability to experience the vaginal orgasm."

No comments:

Post a Comment