G-Spot

© 2010 International Society for Sexual Medicine

Controversies in Sexual Medicine Who’s Afraid of the G-spot?

jsm_1613

25..34

Emmanuele A. Jannini, MD,* Beverly Whipple, PhD, RN, FAAN,† Sheryl A. Kingsberg, PhD,‡ Odile Buisson, MD,§ Pierre Foldès, MD,¶ and Yoram Vardi, MD** *Course of Endocrinology and Medical Sexology, Department of Experimental Medicine, University of L’Aquila, Italy; † Professor Emerita, Rutgers University, NJ, USA; ‡Division of Behavioral Medicine, University Hospitals Case Medical Center, MacDonald Women’s Hospital, Department of Reproductive Biology, Case Western Reserve University School of Medicine Cleveland, OH, USA; §Centre d’échographie, Saint Germain en Laye, France; ¶Hôpital de Saint Germain en Laye, Clinique Louis XIV, Saint Germain en Laye, France; **Neuro-Urology Unit, Rambam Health Care Center and Technion Faculty of Medicine, Haifa, Israel DOI: 10.1111/j.1743-6109.2009.01613.x

ABSTRACT

Introduction. No controversy can be more controversial than that regarding the existence of the G-spot, an anatomical and physiological entity for women and many scientists, yet a gynecological UFO for others. Methods. The pros and cons data have been carefully reviewed by six scientists with different opinions on the G-spot. This controversy roughly follows the Journal of Sexual Medicine Debate held during the International Society for the Study of Women’s Sexual Health Congress in Florence in the February of 2009. Main Outcome Measure. To give to The Journal of Sexual Medicine’s reader enough data to form her/his own opinion on an important topic of female sexuality. Results. Expert #1, who is JSM’s Controversy section editor, reviewed histological data from the literature demonstrating the existence of discrete anatomical structures within the vaginal wall composing the G-spot. He also found that this region is not a constant, but can be highly variable from woman to woman. These data are supported by the findings discussed by Expert #2, dealing with the history of the G-spot and by the fascinating experimental evidences presented by Experts #4 and #5, showing the dynamic changes in the G-spot during digital and penile stimulation. Experts #3 and #6 argue critically against the G-spot discussing the contrasting findings so far produced on the topic. Conclusion. Although a huge amount of data (not always of good quality) have been accumulated in the last 60 years, we still need more research on one of the most challenging aspects of female sexuality. Jannini EA, Whipple B, Kingsberg SA, Buisson O, Foldès P, and Vardi Y. Who’s afraid of the G-spot?. J Sex Med 2010;7:25–34. Key Words. G Spot; Vaginal Orgasm; Vagina; Clitoris; Skene Glands; Female Ejaculation

V

ery few issues in sexology, and now also in sexual medicine, instigate so much reactivity as those related to the female orgasm in general and to G-spot in particular. It is an old story: the goddess Hera blinded the poor Tiresias just because the soothsayer revealed scientific truths on the female orgasm [1]. But some sexologists and feminists are still afraid of the G-spot, considered, with a dramatically prescientific mentality, a male attempt to recoup importance for vaginal penetraJ Sex Med 2010;7:25–34

tion after the celebration of the clitoris during the sexual revolution. Their claims are mostly based on a poorly researched review article, written by an author who is almost unknown in academic medicine and who never published on the field, where the G-spot has been defined as a “a modern gynecologic myth” [2]. Some women are able to reach orgasm without a direct stimulation of the external clitoris but just with the mechanical stimulation of the vagina. 25

Controversies in Sexual Medicine Others do not reach the vaginally activated orgasm, despite different partners and different instruments used. These statements can be hardly denied. The term “G-spot” was used by two researchers, Beverly Whipple (who kindly accepted to write the paragraph on the history of the G-spot) and John D. Perry, to name the sensitive area felt through the anterior vaginal wall, halfway between the back of the pubic bone and the cervix, along the course of the urethra [3]. The data in the available literature have different levels of evidence. 1. Histological studies are very consistent. The G-spot (or area) is composed of individually different amount of cavernosal tissue from the inner clitoris [4], exocrine glands (Skene’s glands, the female counterpart of the prostate [5]), muscles, and nerves within the anterior vaginal wall [6,7]. The urethra seems also to play a major role in the G-spot. The whole biochemical machinery of excitation is especially expressed in these structures (all nitric oxide synthases, phosphodiesterase type 5) [8], as well as specific markers of prostatic tissue (prostate specific antigen (PSA), human protein 1, chromogranin) [7]. In fact, application of alprostadil to the G-spot area is effective in women with female sexual arousal disorder [9]. Studies are in progress to determine how many of these structures and how much are under hormonal (i.e., under testosterone) control changing on the basis of the cycle phase or the menopausal state. The histological “picture” of the G-spot is very well defined, but this “picture” changes when comparing anterior vaginal walls from different women. This explains contrasting data on this anatomical region as well the different ways to define it. Moreover, examinations of vaginal wall innervations have shown that there is no single area with a greater density of nerve endings [10]. A study of 110 biopsy specimens drawn from 21 women concluded that there is no single specific vaginal locus with greater nerve density and thus argued against the G-spot [11]. However, the urethral sponge does contain sensitive nerve endings as well as erectile tissue. Furthermore, it is evident that sensitivity is not determined by neuron density alone. 2. Echo scan imaging [12–14] or urodynamics [15] may be helpful in localizing the G-spot, as reviewed by Buisson and Foldès later in this 26

paper. However, some papers refute the evidence on the G-spot. For instance, Schultz et al. was unable to find by magnetic resonance imaging (MRI) the “widening of the vaginal canal, structures suggesting a Gräfenberg spot, or a separate reservoir of fluid indicating female ejaculation” [16]. However, this statement was based on a single scan obtained from a single woman! 3. Sexual stimulation of the G-spot seems to produce a variety of feelings: discomfort, sensation of urination, or pleasure. With additional stimulation, the area may begin to swell, and then produce an intense orgasm, possibly together with a semen-like (although less viscous) fluid emission, the so-called “female ejaculation,” thought to be the product of Skene’s glands. This part of the story needs more studies and more clear evidence: for instance, the papers which have yielded positive evidence for female ejaculation involve small participant samples [17] and have some methodological biases [18]. 4. The absence (or the low expression of one or more of the G-spot components) is not a disease or a dysfunction: orgasm is achievable by any woman properly stimulated and with a good relationship with her own body and environment. 5. Nomenclature is the final problem: words such as “female ejaculation,” “urethral sponge,” “urethral–vaginal space,” “anterior vaginal wall,” “inner clitoris,” “female prostate,” “Kobelt plexus,” vaginal vs. clitoral orgasm, and G-spot/area itself need to be revised in light of new evidence. A consensus conference of the International Society for Sexual Medicine (ISSM) would be an excellent instrument to accomplish this task. Finally, I have to say few words as rebuttals to the opinions of the two excellent colleagues who are . . . afraid of the G-spot. Dr. Kingsberg is using the elegant argument that “the location of the G-spot is more likely found in a woman’s brain than in her vagina.” Who disagrees? I am sure that humans have sex not only with something between their legs, but definitively with something which is between their ears. Yes, orgasm is a perception, under strict brain control (Is this the reason why orgasm from penetration is frequently referred as deeper than that obtained from the external stimuJ Sex Med 2010;7:25–34

Controversies in Sexual Medicine lation of the clitoris?) but arising from muscular contractions triggered by stimulation of discrete areas . . . between the legs. Dr. Vardi’s main reason to reject existence of the G-spot is the presumed absence of sexual consequences after surgery of this region. I am afraid that, being far from evidence against the G-spot, this argument seems not in favor of some surgeons and of their attention to female sexuality. In any case, I decided to give the last word to Yoram Vardi, as a tribute to an outstanding scientist and gentleman, who was the editor of this section of The Journal of Sexual Medicine, for doing an excellent job, just before me. Emmanuele A. Jannini, MD The Gräfenberg spot or the G-spot was named by Drs. John Perry and Beverly Whipple [19] for the German obstetrician and gynecologist, Dr. Ernst Gräfenberg, who wrote about this sensitive area in 1950 [20]. The G-spot is a sensitive area felt through the anterior wall of the vagina about halfway between the back of the pubic bone and the cervix, along the course of the urethra. It is easiest to feel the G-spot with the woman lying on her back. If one or two fingers are inserted into the vagina, with the palm up, using a “come here” motion, the tissue that surrounds the urethra will begin to swell. When the area is first touched, the woman may feel as if she needs to urinate, but if the touch continues for a few seconds longer, it may turn into a pleasurable feeling. In 1982, Perry and Whipple wrote that “The G-spot is probably composed of a complex network of blood vessels, the paraurethral glands and ducts (female prostate), nerve endings, and the tissue surrounding the bladder neck” [3]. They rediscovered this sensitive area while teaching women Kegel exercises using biofeedback to help treat stress urinary incontinence (SUI). Some of the women reported that they emitted a small amount of fluid from the urethra that was different from urine during sexual activity and these women had very strong pelvic floor muscles, whereas women with SUI have weak pelvic floor muscles [19]. The women with the strong muscles also reported that stimulation of a sensitive area felt through the anterior vaginal wall seemed to trigger this fluid expulsion. Perry and Whipple reported that they then had a physician or nurse practitioner examine 400 women who volunteered to be research subjects. J Sex Med 2010;7:25–34

The G-spot was found in each of these women. However, they cautioned that they could not state with certainty that every woman has a G-spot [3]. They named this area after the first modern researcher to describe its location. A literature search found that Dr. Ernst Gräfenberg described a zone of erogenous feeling that was located along the suburethral surface of the anterior vaginal wall [20]. He later went on to write, “An erotic zone could always be demonstrated on the anterior wall of the vagina along the course of the urethra . . . (which) seems to be surrounded by erectile tissue like the corpora cavernosa (of the penis) . . . In the course of sexual stimulation, the female urethra begins to enlarge and can be easily felt” [20]. Gräfenberg was not the first person to describe this sensitive area; Regnier deGraff, described it in the 17th century, and called it the female prostate or corpus glandulosum. Others have described this area before and since deGraff [3]. Women have reported that they have difficulty locating and stimulating their G-spot by themselves, except with a dildo, a G-spot vibrator, or similar device (there are over 50 such devices now available), but they have no difficulty identifying the erotic sensation when the area is stimulated by a partner. To stimulate the G-spot during vaginal intercourse, the best positions are the woman on top or rear entry, so the average penis will hit the anterior wall of the vagina [21]. Some women describe experiencing orgasm from stimulation solely of the G-spot. The orgasm resulting from stimulation of the G-spot is felt deep inside the body, and a bearing-down sensation, similar to a Valsalva maneuver, during the orgasm is commonly reported [3,22]. Physiologically, the orgasm from G-spot stimulation is different from an orgasm that is produced by clitoral stimulation. During orgasm from clitoral stimulation, the end of the vagina balloons out. During orgasm from G-spot stimulation, the cervix pushes down into the vagina [3]. Many women experience a “blended orgasm” when the G-spot and the clitoris are stimulated at the same time [3]. However, it is important to note that not all women like the feeling of stimulation of the G-spot area. Some women experience an expulsion of a small amount of fluid (about 3–5 cc) from the urethra with G-spot orgasms (as well as with orgasms resulting from stimulation of other areas). The fluid produced by this “female ejaculation” has the appearance of watered-down, fat-free milk. It is 27

Controversies in Sexual Medicine chemically similar to seminal fluid but is different from urine [17,23–25]. Researcher Milan Zaviacic conducted hundreds of studies on autopsy specimens and concluded that the fluid is from the paraurethral glands, which recently have been named the “female prostate gland” [26]. Whipple and Komisaruk stated that, based on research, in some cases, these three distinct entities, the G-spot, orgasm, and female ejaculation, may be related, while in other cases, they are not related [27]. Many men enjoy stimulation of their prostate, which can produce an orgasm that is accompanied by a bearing-down sensation similar to that described by women when they experience an orgasm from G-spot stimulation [3]. Not all researchers have been able to locate the G-spot; thus, there is some controversy about it. Other researchers consider the G-spot obvious. It may be that researchers use different methods of stimulation (and thus obtain different results) in studying the G-spot area or that not all women have a sensitive G-spot area. One group of researchers recently studied 20 women and observed a correlation between vaginal orgasms and the thickness of the “clitoris urethra–vaginal complex also known as the G-spot” [13]. Therefore, pressure exerted against the anterior vaginal wall may be more effective if the G-spot area is thicker, according to this new research. However, the careful terminology (clitoris urethra–vaginal complex) used by the researchers refers to the fact that there are several different organs in this highly complex body region. Komisaruk, Whipple, Nasserzadeh, and Beyer-Flores state that this area may include: (i) the anterior vaginal wall; (ii) the urethra; (iii) the Skene’s glands (including the paraurethral glands or female prostate gland); (iv) perhaps the other glands in this region (vestibular glands, Bartholin’s glands); (v) the surrounding muscle and connective tissue; and (vi) perhaps the crura of the clitoris [28]. The effect of G-spot stimulation might primarily be the result of stimulation of just one structure (such as the female prostate gland) or it might be the result of stimulation of several sensitive structures that are close together. More recent research from our laboratories has documented that self-stimulation of the area of the G-spot produces a very strong analgesic effect, which is also activated naturally during labor. We have documented, using functional MRI of the brain, that orgasm from self-stimulation of the area of the G-spot activates the same brain regions 28

in women with and without complete spinal cord injury (SCI) as are activated during orgasm from self-stimulation of the cervix of the uterus. The same brain regions are also activated in women without SCI during orgasm from G-spot selfstimulation, from clitoral self-stimulation, and from imagery alone, with no touching of the body (see [29] for review). There is much more to be studied in terms of female sexual responses and it behooves researchers to listen to women and then to validate their pleasurable sensual and sexual experiences in laboratory studies. As has been written in the final chapter of the first book on The G-spot, if G-spot stimulation feels good, then women should enjoy it, but they should not feel compelled to find the G-spot. This is not a goal that women and their partners should strive to achieve [3]. Women need to be encouraged to enjoy what they find pleasurable and not set up finding the G-spot or experiencing orgasm or female ejaculation as a goal. People need to be encouraged to regard the G-spot as one area of sensual and sexual pleasure that some women enjoy. Beverly Whipple, PhD, RN, FAAN Rarely has a debate over the existence or not of an anatomical structure garnered such vast attention from the general (dare I say lay) public as the controversy over the G-spot. In fact, thanks to Ladas, Whipple, and Perry’s 1982 hit book, The G-spot and Other Recent Discoveries about Human Sexuality [3], the G-spot has become a cultural truism. Had it not been for the wide acceptance of the G-spot’s existence, where would it be today in sexual medicine (i.e., would we be able to find it)? Would it have fallen into obscurity along with other theories based on little scientific evidence? It is ironic that Gräfenberg’s hypothesis [20] has been used to provide anatomical support for one such theory with little methodologically rigorous evidence—Freud’s theory of the vaginal orgasm. This “vaginal transfer theory” holds that clitoral responsivity must be superseded by vaginal orgasm in mature women. Is this an example of the blind leading the blind or the blind leading to going blind if a woman touches her own G-spot? While my colleagues have been charged with the task of debating the existence of the G-spot as an anatomical area located on the anterior wall of the vagina one-third of the way up from the vaginal opening, my task is to address the question J Sex Med 2010;7:25–34

Controversies in Sexual Medicine of whether the G-spot should more accurately be considered a placebo response. From a pragmatic perspective, as an anatomical structure, it has not been easily been made evident, albeit allowing for a pronoun shift from an “it” to a “there,” reflecting the concept of a sensitive “area.” The neurophysiology of the vagina itself is poorly understood and there is scant evidence to support the hypothesis that vaginal innervation is correlated with sexual sensation and function [11]. One of the major sources of data in support of the existence of a G-spot has been from associated research investigating the existence of female ejaculation and the supposition that the parauerthral (Skene’s) glands are the female equivalent of a prostate [4]. Other researchers have suggested that stimulation of the G-spot results in sexual pleasure due to its proximal location to the bulbs of the clitoris [30]. A second source of support has been from research using behavioral methodology, again a downstream source of evidence. These are reports of intense pleasurable sensation and intense orgasms as the result of stimulation of the G-spot area. For example, Addiego et al. [17] presented the first report case report of a woman for whom stimulation of the anterior vaginal wall made the area expand by 50%, and that self-reported levels of arousal/orgasm were “deeper” when the G-spot was stimulated. Goldberg et al. [31] examined 11 women by palpating the entire vagina in a clockwise fashion. They reported a specific response to stimulation of the anterior vaginal wall in four of the women. However, even under the most rigorous of experimental methods, it is difficult to reach the G-spot without “accidentally” stimulating other areas along the way. This would be absolutely the case in a nonexperimental, sexual encounter using a finger, penis, or other objects de pleasir. The excitement generated by the potential existence of a G-spot is due to the theory that stimulation supposedly results in high levels of pleasurable sexual sensations and powerful orgasms [3]. Therefore, I propose that the location of the G-spot is more likely found in a woman’s brain than in her vagina. In other words, I submit that the G-spot is inaccurately named and should instead be more correctly labeled the P-spot where P stands for placebo. A placebo effect is a medical phenomenon in which an inactive substance like sugar or distilled water or even a designated “spot” improves a condition simply because a person has J Sex Med 2010;7:25–34

the expectation that it will. Placebos have measurable physiologic effects. For example, if subjects will speed up their pulse rate, increase their blood pressure, and improve reaction time after being told they have taken a stimulant, imagine the effect of telling a subject what stimulating the G-spot is supposed to do! Beliefs about what effect the placebo will have are related to changes in the body’s neurological regulatory systems found in the higher cerebral cortex. Furthermore, although stimulation of the G-spot is considered to result in intense orgasms (so strong, in fact, as to relegate the clitoral orgasm to second-class status), researchers still have no definitive explanations for what triggers orgasm [32]. Therefore, if female orgasm is so nebulous, how confident can we be about a G-spot? Sheryl A. Kingsberg, PhD The existence of the G-spot remains controversial partly because no appropriate structure and innervation have been clearly demonstrated in this pleasurable vaginal area. Recently, Gravina et al. demonstrated that the thickness of the urethrovaginal space is larger with women who have a vaginal orgasm than with women who have a clitoral orgasm [13]. It is now scientifically proven that there is an objective anatomical difference. However, the cause of the difference in the thickness of this space remains unclear. Dynamic sonography can provide us with more facts about the G-spot area. We placed a 12-MHz sonographic probe on the top of the vulva of a healthy 40-year-old woman, capable of achieving vaginal orgasms (i.e., without direct stimulation of the external clitoris) with no sexual dysfunction. We made a triplanar 3-D reconstruction of her clitoris. The coronal planes of what O’Connell names the “clitoral complex” [4] contain the most information. It demonstrates a series of triangles: cavernous bodies, venous Kobelt plexus, bulbs (because bulbs are located discreetly posteriorly in the root of the clitoris and then descend anteriorly) and, lastly, symphysis [12] (Figure 1). In fact, venous Kobelt plexuses are entrapped between the double vault formed by cavernous bodies and bulbs. Sonography demonstrates that a finger vaginal penetration evokes a reflex perineal contraction and tightly narrows the distance between the root of the clitoris (cavernous bodies and bulbs) and the distal anterior vaginal wall. When the patient locates her own G-spot 29

Controversies in Sexual Medicine

Figure 1 Echo scan of human vagina. The triplanar 3-D reconstruction demonstrates a series of triangles: cavernous bodies, venous Kobelt plexus, bulbs (because bulbs are located discreetly posteriorly in the root of the clitoris and then descend anteriorly) and, lastly, symphysis. CB = clitoral body; BU = bulb; K = Kobelt plexus; VA = vagina.

with her finger, the echoes of the finger are found at close proximity to the clitoris root and the pressure movement of the finger displaces cavernous bodies and bulbs [14] (Figure 2). If the root of the clitoris containing cavernous bodies, venous Kobelt plexuses, and bulbs are related to the anterior vaginal wall, why would it not play a part in the vaginal pleasure? Under erotic stimulation, neuromuscular reflex [33] and vasomotor events [34] have been demonstrated. We suggest that these events could increase the contact between the vagina and the richly inner-

Figure 2 Echo scan of the human vagina during digital stimulation. Coronal plane of the root of the clitoris: when the patient locates her own G-spot with her finger, the echos of the finger are found at close proximity to the clitoris root and the pressure movement of the finger displaces cavernous bodies and bulbs. GL = glans; CB = clitoral body; BU = bulb.

30

vated and congestive clitoris. To date, it is not possible to visualize the clitoris during an MRI coitus [35], but a sonography of an erected penis penetration allows visualization of the clitoralcomplex modification. We performed the ultrasounds during the coitus of a volunteer couple with the Voluson General Electric Sonography system (Solingen, Germany), a 12-MHz flat probe. The woman was in gynecologic position and her companion penetrated her from a standing position. We performed a coronal section on the top of the vulva during the penetration. It becomes obvious that the coitus creates a completely different anatomical entity due to modification of the way in which the organs are related to each other. The sonography of the coitus provides us with the following findings: the root of the clitoris is ascending and completely widened by the penis. During the thrusting, the anterior vaginal wall is crushed against the root of the clitoris (Figure 3). The Kobelt plexus is a venous plexus entrapped between the clitoral bodies and the bulbs. It is well visualized during the coitus and seems to be repeatedly crushed by the pressure of the penis. It is likely that a venous pumping effect exists at this specific location: on the top of the double vault made of the two cavernous bodies and the two bulbs. It is very easy to measure the cavernous bodies and to see the enhanced clitoris’s size as shown with MRI [36]. The special location of the Kobelt plexus seems also interesting: first, it is located on the top of the J Sex Med 2010;7:25–34

Controversies in Sexual Medicine

Figure 3 Echo scan of the human vagina during coitus. Coronal plane of the coitus. The probe is placed transversally on the top of the vulva in a coronal inclination. The cavernous bodies are enlarged and pushed up. The bulbs are partially hidden by the erected penis. Venous Kobelt plexuses are in a special location on the top of the vault. The clitoral complex is crushed by the erected penis against the anterior vaginal wall. The plane of the three parts of the erected penis is well visualized. BU = bulb; CB = clitoral body; K = Kobelt plexus; CC = corpus cavernosum.

double vault which is situated on the G-spot area, then it drains toward vaginal veins and, second, it seems to have a particular venous organization. Enlarging a sonographic image of the Kobelt plexus of a quiescent clitoris, we can see distinctly the blood whirl; it seems as if there is a kind of stagnation followed by slow, periodical, and

repeated releases of the blood. With Color Doppler, on a coronal view, a discontinuous but regular color signal in the Kobelt plexus is visualized. Measurements demonstrate that the releasing flow is very slow: about 5 cm per second. There is no flow between the releases as if the Kobelt plexus played the role of a reservoir for a short time (Figure 4). The Kobelt plexus is repeatedly crushed during the thrusting of the penis in an area which is full of neurotransmitters [6]. These evidences lead us to ask four questions: (i) During the coitus, does the root of the clitoris compressing the Kobelt plexus create a venous pumping effect and an accumulation of neurotransmitters?; (ii) Does the Kobelt plexus play the role of a kind of reservoir from which the accumulated neurotransmitters are released at a certain moment?; (iii) Does this release of accumulated neurotransmitters cause the sensation perceived as vaginal orgasm?; (iv) Does the root of the clitoris participate to the vaginal orgasm, with different neurologic pathways than those for the clitoral orgasm? Medical images open the gate toward a reconceptualization of the G-spot. The G-spot is probably not a unique anatomical structure but rather a functional one which involves the clitoral complex and the vagina during a vaginal penetration. Part of the solution to a better understanding of the female sexuality lays undoubtedly in functional imagery [37]. Odile Buisson, MD and Pierre Foldès, MD

Figure 4 Color Doppler of the human vagina. The signal of the venous Kobelt plexuses on a quiescent clitoris: there is no flow between the repetitive releasing of blood, as if the Kobelt plexuses played the role of a reservoir for a short time. BU = bulb; CB = clitoral body; K = Kobelt plexus.

J Sex Med 2010;7:25–34

31

Controversies in Sexual Medicine It was in the early 1950s that the importance of the anterior vaginal wall became evident in regard to sexual pleasure and orgasm. This can be attributed to the German gynecologist Ernst Gräfenberg [20] who described the existence of an area of high sensitivity in the anterior vagina, later named the G-spot. Sixty years later, there is still a wide discrepancy between the questionable existence of the G-spot on one hand and the mass popularity and its empowerment on the other. The first attempt to investigate the existence of the G-spot was performed by Goldberg et al. [31] using a standardized manual technique. This study was conducted by two trained gynecologists in 11 women. Using their methodology, they found the G-spot in four of them. Other sexology literature provides only testimonials and anecdotal reports on the G-spot that describes it as different, providing sexual arousal and pleasure. On the other hand, others have demonstrated that also the posterior vaginal wall can similarly elicit an orgasmic response [38]. Anatomical Concern

Scientific anatomical and imaging evidence for the existence of the G-spot are quite poor. The only anatomical structures identified in this area are the Skene’s glands that may play a role in the stimulatory phase of the sexual response and orgasm in this region. However, no receptors for touch stimulation and no direct evidence for their involvement in sensory input have been documented [39]. Data available today do not provide any supporting evidence that these glandular structures are part of the area named the G-spot. For many women, the anterior wall of the vagina is an erogenous zone and one of the explanations for its higher sensitivity may be the proximity to the clitoral cavernosal tissue. Mechanical pressure on the anterior vaginal wall could indirectly stimulate clitoral structures enhancing sensation of pleasure. This theory has been investigated by Foldès et al. using ultrasonography [14]. Other imaging modalities, such as magnetic resonance, was used during sexual arousal but did not show any significant change in the signal intensity, nor did find any distinct anatomical structure in this area [16,40]. Recently, some direct anatomical evidence for the existence of the G-spot as a separate anatomical entity was suggested by Jannini et al. [13] who 32

described differences in the thickness of the “urethrovaginal space” which was detected by ultrasonic measurement, in 20 healthy female volunteers. The urethrovaginal space was found to be thinner in females without vaginal orgasm compared with those who did experience vaginal orgasm (nine and 11, respectively). He speculated that a functional correlation between the thickness of the “urethrovaginal space” (G-spot) and the ability to experience vaginal orgasm may exist. Nevertheless, he was unable to directly demonstrate that the thickness of this anatomical “space” generates any mechanism related to the initiation or involvement of orgasm. Apart from Jannini’s report, I did not find studies that were able to show or describe the G-spot anatomically. Moreover, studies which evaluated biopsies from this area did not demonstrate nerve ending condensation compared with other regions in the vagina [41]. From an anatomical and histological point of view and from the data available, it seems that only very poor evidence for the existence of a distinct anatomical structure that can be defined as a G-spot exist. Sexual Function Postvaginal Surgery

One would assume that gynecological or urological interventions in the anterior vaginal wall would adversely affect sexual function, especially when considering the possible existence of the G-spot in this location. Extensive dissection of the anterior vaginal wall is commonly performed during procedures such as mid-urethral slings, or repair of anterior vaginal wall prolapse. These and similar surgical interventions have the potential to damage the nerve supply to this area. There is no current study showing changes in genital sensation following mid-urethral sling or prolapse repair. Moreover, when evaluating sexual functioning in women who underwent these types of surgeries, a significant improvement in sexual function was claimed following the repair of anterior vaginal wall prolapse [42]. This fact is a strong argument against the existence of a distinct anatomical region in the anterior vagina responsible for sexual pleasure and orgasm. Conclusions

From a scientific standpoint, there is poor evidence to confirm the existence of the G-spot. J Sex Med 2010;7:25–34

Controversies in Sexual Medicine Objective measures such as MRI and ultrasound did not provide solid evidence to the existence of the legendary G-spot. On the other hand, selfreported levels of arousal during stimulation, numerous reliable reports and anecdotal testimonials of its existence are available. Another problematic aspect of the “search for the G spot,” especially with regard to social pressure and media coverage, is the fact that many women unable to reach a vaginal orgasm may become frustrated and sexually handicapped in their obsessive search for it. Even more problematic is the fact that some professionals take advantage of the cultural glorification of the G-spot, and offer interventions such as “G-spot augmentation.” Only time will tell if science or human nature and future sexual experiences will provide more information regarding the existence of this mysterious structure but will undoubtedly continue to occupy the public’s imagination. Yoram Vardi, MD Corresponding Author: Emmanuele A. Jannini, MD,Course of Endocrinology and Medical Sexology, Department of Experimental Medicine, University of L’Aquila, L’Aquila, 67100, Italy. Tel: +39 0862433530; Fax: +39 0862433523; E-mail: emmanuele.jannini@ univaq.it References

1 Loraux N. The experiences of Tiresias. The feminine and the Greek man. Princeton, NJ: Princeton University Press; 1995. 2 Hines TM. The g-spot: A modern gynecologic myth. Am J Obstet Gynecol 2001;185:359–62. 3 Ladas AK, Whipple B, Perry J. The G-spot and other recent discoveries about human sexuality. New York: Holt, Reinehart & Wiston; 1982. 4 O’Connell HE, Eizenberg N, Rahman M, Cleeve J. The anatomy of the distal vagina: Towards unity. J Sex Med 2008;5:1883–91. 5 Zaviacic M, Ablin RJ. The female prostate. J Natl Cancer Inst 1998;90:713–4. 6 Jannini EA, d’Amati G, Lenzi A. Histology and immunohistochemical studies of female genital tissue. In: Goldstein I, Meston C, Davis S, Traish A, eds. Women’s sexual function and dysfunction: Study, diagnosis and treatment. London: Taylor and Francis; 2006:125–33. 7 D’Amati G, di Gioia CR, Proietti Pannunzi L, Pistilli D, Carosa E, Lenzi A, Jannini EA. Functional anatomy of the human vagina. J Endocrinol Invest 2003;26:92–6.

J Sex Med 2010;7:25–34

8 D’Amati G, di Gioia CR, Bologna M, Giordano D, Giorgi M, Dolci S, Jannini EA. Type 5 phosphodiesterase expression in the human vagina. Urology 2002;60:191–5. 9 Liao Q, Zhang M, Geng L, Wang X, Song X, Xia P, Lu T, Lu M, Liu V. Efficacy and safety of alprostadil cream for the treatment of female sexual arousal disorder: A double-blind, placebo-controlled study in Chinese population. J Sex Med 2008;5:1923–31. 10 Hoyle CH, Stones RW, Robson T, Whitley K, Burnstock G. Innervation of vasculature and microvasculature of the human vagina by NOS and neuropeptide-containing nerves. J Anat 1996;188: 633–44. 11 Pauls R, Mutema G, Segal J, Silva WA, Kleeman S, Dryfhout Ma V, Karram M. A prospective study examining the anatomic distribution of nerve density in the human vagina. J Sex Med 2006;3:979–87. 12 Buisson O, Foldes P, Paniel BJ. Sonography of the clitoris. J Sex Med 2008;5:413–7. 13 Gravina GL, Brandetti F, Martini P, Carosa E, Di Stasi SM, Morano S, Lenzi A, Jannini EA. Measurement of the thickness of the urethrovaginal space in women with or without vaginal orgasm. J Sex Med 2008;5:610–8. 14 Foldes P, Buisson O. The clitoral complex: A dynamic sonographic study. J Sex Med 2009;6: 1223–31. 15 Cartwright R, Elvy S, Cardozo L. Do women with female ejaculation have detrusor overactivity? J Sex Med 2007;4:1655–8. 16 Schultz WW, van Andel P, Sabelis I. Mooyaart E. Magnetic resonance imaging of male and female genitals during coitus and female sexual arousal. BMJ 1999;319:1596–600. 17 Addiego F, Belzer EG, Comolli J, Moger W, Perry JD, Whipple B. Female ejaculation: A case study. J Sex Res 1981;17:13–21. 18 Davidson JK Sr., Darling CA, Conway-Welch C. The role of the Grafenberg spot and female ejaculation in the female orgasmic response: An empirical analysis. J Sex Marital Ther 1989;15:102–20. 19 Perry JD, Whipple B. Pelvic muscle strength of female ejaculators: Evidence in support of a new theory of orgasm. J Sex Res 1981;17:22–39. 20 Grafenberg E. The role of the urethra in female orgasm. Int J Sexol 1950;3:145–6. 21 Ladas AK, Whipple B, Perry JD. The G spot and other discoveries about human sexuality. New York: Owl Books; 2005. 22 Weisberg M. A note on female ejaculation. J Sex Res 1981;17:90. 23 Belzer EG, Whipple B, Moger W. On female ejaculation. J Sex Res 1984;20:403–6. 24 Zaviacic M, Kokavec M, Zaviacicova A, Blazerova J, Hholoman IK. Forensic-medical aspects of female 33

Controversies in Sexual Medicine

25

26

27

28 29 30

31

32 33

34

prostate and female ejaculation: Acid phosphatse positivity in the artificially prepared spots from fluid expelled at ejaculation of the female. Arch Med Sad Krym 1987;37:152–9. Cabello F. Female ejaculation: Myths and reality. In: Borras-Valls JJ, Perez-Conchillo M, eds. Sexuality and human rights. Valencia: Nau Llibres; 1997:1– 8. Ziviacic M. The human female prostate: From vestigial Skene’s paraurethral glands and ducts to woman’s functional prostate. Bratislava, Slovakia: Slovak Academic Press; 1999. Whipple B, Komisaruk BR. The G spot, orgasm and female ejaculation: Are they related? In: P. Kotari, ed. Proceedings of the first international conference on orgasm. Bombay, India: VRP Publishers; 1991:227–37. Komisaruk BR, Whipple B, Nasserzadeh S, BeyerFlores C. The orgasm answer guide. Baltimore: Johns Hopkins University Press; in press. Komisaruk BR, Beyers-Flores C, Whipple B. The science of orgasm. Baltimore: Johns Hopkins University Press; 2006. Tepper SL, Jagirdar J, Heath D, Geller SA. Homology between the female paraurethral (Skene’s) glands and the prostate. Immunohistochemical demonstration. Arch Pathol Lab Med 1984;108: 423–5. Goldberg DC, Whipple B, Fishkin RE, Waxman H, Fink PJ, Weisberg M. The Grafenberg spot and female ejaculation: A review of initial hypotheses. J Sex Marital Ther 1983;9:27–37. Meston CM, Levin RJ, Sipski ML, Hull EM, Heiman JR. Women’s orgasm. Annu Rev Sex Res 2004;15:173–257. Levin RJ. The physiology of sexual arousal in the human female: A recreational and procreational synthesis. Arch Sex Behav 2002;31:405–11.

34 Shafik A. Vaginocavernosus reflex. Clinical significance and role in sexual act. Gynecol Obstet Invest 1993;35:114–7. 35 Faix A, Lapray JF, Courtieu C, Maubon A, Lanfrey K. Magnetic resonance imaging of sexual intercourse: Initial experience. J Sex Marital Ther 2001; 27:475–82. 36 Maravilla KR, Cao Y, Heiman JR, Yang C, Garland PA, Peterson BT, Carter WO. Noncontrast dynamic magnetic resonance imaging for quantitative assessment of female sexual arousal. J Urol 2005;173:162–6. 37 Maravilla KR, Yang CC. Magnetic resonance imaging and the female sexual response: Overview of techniques, results, and future directions. J Sex Med 2008;5:1559–71. 38 Alzate H. Vaginal eroticism: A replication study. Arch Sex Behav 1985;14:529–37. 39 Alzate H. Vaginal erogeneity, “female ejaculation,” and the “Grafenberg spot.” Arch Sex Behav 1990;19:607–11. 40 Gutman RE, Pannu HK, Cundiff GW, Melick CF, Siddique SA, Handa VL. Anatomic relationship between the vaginal apex and the bony architecture of the pelvis: A magnetic resonance imaging evaluation. Am J Obstet Gynecol 2005;192:1544– 8. 41 Hilliges M, Falconer C, Ekman-Ordeberg G, Johansson O. Innervation of the human vaginal mucosa as revealed by PGP 9. 5 immunohistochemistry. Acta Anat (Basel) 1995;153:119– 26. 42 Fayyad AM, Redhead E, Awan N, Kyrgiou M, Prashar S, Hill SR. Symptomatic and quality of life outcomes after site-specific fascial reattachment for pelvic organ prolapse repair. Int Urogynecol J Pelvic Floor Dysfunct 2008;19: 191–7.

J Sex Med 2010;7:25–34