Table 2.

Studies on clinical, anatomical, imaging, surgical, or histological evidence of the existence of the G-spot

Author	Country	Year	Type of study	N =	Age range	Results
Perry J et al.24	USA	1981	•Vaginal and uterine myograph to evaluate EMG levels •Women recruited by sex therapists, educators and councilors •Questionnaire (Likert scale, Sexual Arousal Inventory) •Digital examination of the pubococcygeus muscle •Two finger palpation of the whole anterior wall (G-spot), sometimes with abdominal pressure	47	21-63 (mean 34)	•G-spot identified in all subjects in the anterior wall (most at 12 o'clock) •1 cm deep in the vaginal wall •Swelling upon stimulation (can take more than 1 minute)
Goldberg D et al.27	USA	1983	•Self-recruited women (newspapers, talk shows)	11 (6 self-identified as ejaculators)	24-61	•G-spot identified in 4/11 (36%) women •No differences between ejaculators and nonejaculators
Alzate H25	Colombia	1985	•Digital exploration of both vaginal walls •Healthy women (82% sex workers)	27	(mean 24.1±4.2)	•89% had an orgasmic response in response to vaginal stimulation (not a specific area) – findings do not support the existence of a G-spot, but rather the existence of clitoral and vaginal orgasms •85% reported it in the posterior wall (mostly in the lower half) and 74% in the anterior one •Of the ones who had erotic sensitivity in the anterior wall, 100% referred it in the upper half and 60% in the lower half of the vagina) •No perception of “swollen structures) •Some of the women who reached orgasm with stimulation of the posterior wall also did it with anorectal stimulation •No evidence of ejaculation •(Bias: mostly sex workers)
Hoch Z(25)	Israel	1986	•Women with coital anorgasmia but orgasmic with external genitalia stimulation •Israeli Minnesota Multiphasic Psychological Inventory, Bem Sex-Role Inventory, Sim-Fam game, anthropometric measures of sexual dimorphism, detailed sociological questionnaire, Lief and Ebert Sexual Performance Evaluation Questionnaire •Sexual examination of the vagina (finger) – performed by the investigator and partner	56	19-64	•No evidence of a G-spot •96% with pleasure upon exploration of the entire anterior vaginal wall, including the deeper situated urinary bladder, periurethral tissues and Halban's fascia •6% with exploration of the cervix, 3% in the posterior wall of the vagina and 2% in the lateral vaginal walls (4–8 h) •64% orgasmic with stimulation of the anterior vaginal wall •(Bias: anorgasmic women)
Zaviačič M et al.23	Czechoslovakia	1988	•Mostly women referred for infertility •Questionnaire •Digital stimulation (1-2 fingers) (in 2 “hard-to-induce expulsions” cases a vibrator was used	27	20-40	•G-spot identified in all the participants, in the anterior vaginal wall •Tumescence of the spot upon stimulation •37% ejaculated
Whipple B et al.28	USA	2002	•Women with midthoracic complete spinal cord injury •Brain PET-MRI during cervical and vaginal self-stimulation	2 women with SCI and one for control		•All had activation of the region of the nucleus of the solitary tract, via vagus nerve (by-pass of the spinal cord)
D'Amati G et al.29	Italy	2002	•Immunohistochemistry (antibodies against 5 phosphodiesterase [PDE5]) performed on vaginal tissue obtained at autopsy and on scraped cells from the anterior vaginal epithelium of healthy female donors	14 vaginal specimens obtained at autopsy 5 vaginal samples from healthy donors	18-40 (mean 30.0±3.6) 24-38 years	•PDE5 immunoreactivity was mostly localized in the smooth muscle of vessels, forming a pseudocavernous tissue in the vaginal wall and endothelium •It was also present in exfoliated vaginal cells and Skene glands •cavernous or pseudocavernous tissue within the vaginal wall was observed in 12/14 (86%) •Skene glands identified in 9/14 (64%)
Shafik A et al.30	Egypt	2003	•Healthy volunteers •Electrovaginogram and manometry	24	26-52 (mean 28.6±8.2)	•Electrical waves detected in the proximal vagina (pacemaker) •Intensity responsive to vaginal pressure
Foldes P et al.31	France	2007	•Healthy volunteers •Vaginal ultrasound with doppler •Placement of a hyperecogenic stick in the supposed area of the clitoris	Not referred	38-48	•Identification of a hyperecoic area between the clitoris and the vagina and two lateral hypoecoic areas (cavernous veins) •Descending movement of these structures with the contraction of the levator ani.
Gravina G et al.32	Italy	2009	•Healthy women with and without vaginal orgasm •Urodynamic study •Ultrasound for evaluation of the urethrovaginal space thickness	20 (9 with vaginal orgasms, 11 without vaginal orgasm)	29-36	•The urethrovaginal space and distal, middle, and proximal urethrovaginal segments were thinner in women without vaginal orgasm •Correlation between thickness and vaginal orgasm (higher for the distal segment) •Excellent correlation between observers
Thabet S(16)	Egypt	2009	•Evaluation of women with cystocele, prior to surgery •Evaluation of the circumcision and anterior vaginal surgery in the function of the G-spot •Preoperative “sexual examination” to map the G-spot •Pre and post-operatory sexual function assessment (Kasr El Aini Sexual Assessment Sheet) •Histological examination of surgical specimens	175 (125 circumcised and 50 noncircumcised)	25-35	•Functional evidence of the presence of the G-spot in 82,3% • Anatomical evidence in 65.9% •Histological evidence (epithelial, glandular and erectile tissue) in 47.4% •Ejaculation in 12.6% •Sex scores higher in women with histological evidence of the G-spot •Significant drop in sex scores after anterior vaginal wall surgery •Circumcision rarely affects the G-spot function
Song Y et al.33	Korea	2009	•Microdissection and protein gene product (PGP) 9.5 immunohistochemistry of the vagina of fresh cadavers	7	50-81 (mean 66.63±12.11)	•Terminal nerve branches in the vaginal wall were most dense at the second 1/5 partition from the inferior anterior wall •Lower density at the fourth partition and scarcity in the fifth 1/5 partitions from the bottom •The mucosa and the vaginal muscle were thicker in the distal third of the vagina •Small and large nerve fibers more common in the distal third of the vagina •The second 1/5 partition of the distal anterior wall had significantly richer innervation •The authors assume the 1/5 partition of the distal anterior wall as the G-spot
Foldes P et al.34	France	2009	•Dynamic sonographic of the clitoris (flat and vaginal probe) •Healthy, heterosexual, sexually active women reporting vaginal orgasm and having a G-spot •No contraception •Observation between day 4–12 of the cycle •No sexual dysfunction •Evaluation of the size of the clitoris and of its movements during voluntary perineal contractions and finger pressure in the most pleasurable area of the vagina (without stimulation)	5	34	•During perineal contraction and finger penetration, the coronal planes demonstrated a close relationship between the root of the clitoris and the anterior vaginal wall (descending movement of 2.5–5 mm) •The G-spot may be the root of the clitoris •No glandular structures visualized along the urethra
Battaglia C et al.35	Italy and Spain	2010	•2D and 3D translabial ultrasound evaluation of the clitoris and urethrovaginal space, without sexual stimulation •Women on a stable heterosexual relationship, sexually active, and without sexual dysfunction •Eumenorrheic women with and without vaginal orgasm	39 women: •19 with vaginal orgasm •20 without vaginal orgasm	24-30	•The 3D reconstruction showed the presence of a gland-like structure (“female prostate”) in the urethrovaginal space, with small vessels feeding it •Length and volume e structures contained in the urethrovaginal space were significantly higher in women who experienced vaginal orgasms •Volume of these structures correlated with time since intercourse, levels of testosterone and androstenedione •The authors do not assume this area as the G-spot, but rather as a system of glands and ducts
Battaglia C et al.36	Italy and Spain	2010	•2D and 3D translabial ultrasound evaluation of the clitoris and urethrovaginal space, without sexual stimulation •Women on a stable heterosexual relationship, sexually active, and without sexual dysfunction •Lean women with PCOS vs. eumenorrheic women •No hormonal therapies in the previous 6 months	48 women: •23 with PCOS •25 eumenorrheic	18-35	•The 3D reconstruction showed the presence of a gland-like structure (“female prostate”) in the urethrovaginal space, with small vessels feeding it •This structure was larger in women with PCOS •Size of the “female prostate” correlated with time since intercourse, length of the urethrovaginal space and levels of testosterone •Middle portion of the urethra significantly thicker in women with PCOS •No differences in terms of vascularization or clitoral body volume •No differences in terms of vaginal orgasm (56 vs. 52%) •The authors do not assume this area as the G-spot, but rather as a system of glands and ducts
Buisson O et al.13	France	2010	•Ultrasound of the anterior vaginal wall during coitus •Coronal section on the top of the vulva during the penetration using a flat probe •Woman not using contraception •Exam performed during the late follicular phase	1 couple	Not referred	•The penis inflated the vagina and stretched the root of the clitoris, thus becoming in a very close relationship with the anterior vaginal wall (clito-urethrovaginal complex), moving and pressuring it against the pubic symphysis. •This could explain the pleasurable sensitivity of this anterior vaginal area. •The authors assume the clito-urethrovaginal complex is the G-spot)
Ostrzenski A.9	USA	2012	•Stratum-by-stratum vaginal wall dissection on a fresh cadaver	1	83	•The G-spot has a distinguishable anatomic structure that is located on the dorsal perineal membrane, 16.5 mm from the upper part of the urethral meatus •The lower pole and the upper pole were located 3 and 15 mm next to the lateral border of the urethra •Appearance of a well-delineated sac with walls that resembled fibroconnective tissues and resembled erectile tissues. •Upon opening the sac blue grape-like anatomic compositions of the G-spot emerged with dimensions of 8.1 × 3.6–1.5 × 0.4 mm (stretchable to 33 mm). •The G-spot structure had three distinct areas •From the distal tail, a rope-like structure (vessel) emerged, which was seen for approximately 1.6 mm and then disappeared into the surrounding tissue. •Limited mobility together with the dorsal perineal membrane on which the G-spot was situated
Thabet S15	Egypt	2013	•Prospective, randomized •Clinical examination, operative findings and histopathological examination of surgical specimens (n=350) •Kasr El Aini Sexual Questionnaire Sheet	1500 women: •500 had vulvar/vaginal surgery •1000 outpatients •(39 with vaginal agenesis)	20-35	•52.7% with local response upon examination (“irritation” and protrusion) •Localized structure in 58% and diffuse in the rest •Ejaculation in 100% of those with a localized G-spot and in 24.5% if diffuse •100% histologically proved (“erectile tissue”) •100% of the cases with connection with the hymen •Pictures in the paper localize the “G-spot bodies” in the vulvar, below the urethral meatus.
Buisson O et al.12	France, Italy	2013	•Ultrasound evaluation of the “clitorourethrovaginal complex” using a vaginal (sagittal plane) and a linear probe •Functional sonography of the stimulated clitoris (manual self-stimulation of the external clitoris or during vaginal penetration with a wet tampon) •Heterosexual women, sexually active, in a stable relationship	3	27-33	•The sagittal scans obtained during external stimulation and vaginal penetration demonstrated that the root of the clitoris is not involved with external clitoral stimulation (vaginal wet tampon immobile when external clitoral stimulation was performed) •During vaginal stimulation, the whole CUV complex and the clitoral roots in particular are involved •The color signal indicating flow speed in the veins •mirrored the anatomical changes.
Li T et al.37	China	2014	•Biopsies of the distal- and proximal-third of the anterior vagina •Women with stress urinary incontinence or pelvic organ prolapse •H&E, neural marker protein gene product 9.5 and smooth muscle actin	32	41-77	•Increased density of small nerves and microvessels in the distal-third of the anterior vaginal wall •Small nerve fibers detected in the lamina propria and muscle layers of distal- and proximal-third areas. •Nerve bundles less abundant in the muscle layer and rarely appeared in the lamina propria. •No small vessels in the lamina propria and few in the muscle layer
Ostrzenski A et al.38	USA, Poland	2014	•Fresh human cadavers •Anterior vaginal wall dissections and G-spot •All specimens stained with haematoxylin and eosin •Two random cases selected at random for immunohistochemical staining	8	•37-68	•The G-spot was identified in all women and was in a diagonal plane •The G-spot complex was located within the distal anterior vaginal wall (average 4.5 cm from the urethral meatus) and has 3 fused parts •In seven (87.5%) it was on the left side and in one (12.5%) on right side •Angle with the urethra ranging between 18-35° •The G-spot was intimately fused with vessels •Sac thickness <2 mm •A vein-like vascular structure with a few smaller feeding arteries was identified •A band-like structure protruded from the tail of the G-spot. •z.bull; The size of the G-spot was variable (mean 7 mm) and could expand on average of 5 times •Histologically, the G-spot was determined as a neurovascular complex structure within a fibroadipose tissue bed. •The neural component contained abundant peripheral nerve bundles and a nerve ganglion. •The vascular component comprised large vein-like vessels and smaller feeding arteries and resembled arteriovenous malformations. •The vascular component did not resemble erectile tissue •Circular and longitudinal muscles covered the G-complex.
Ostrzenski A(34)	USA	2014	•Prospective case series on fresh female cadavers •Anterior vaginal wall stratum-by-stratum macro-dissections •The G-spot tissues were stained with hematoxilin and eosin for histology	11	27-83	•The cylindrical G-spot complex was identified in all subjects on the distal vagina •More often on the left side8 of the margin of the urethra •Localized laterally to the urethra (distance between tail and urethra 3.1 to 5.7 mm) •5.5 cm from the urethral meatus •Mean size of 8±5 mm, expanding an average 5 times when released from the sac •Diagonal orientation plane with an angle of 18-35° •Sac wall with a thickness of 1.6±0.4 mm and merges with the anterior vaginal wall •At the lower pole of the G-spot, a tiny band-like structure was identified, grossly resembling a vascular structure •Blood vessels with ability to expand •The G-spot complex expansion elevated the anterior vaginal walls in all subjects (vascular distention) •The autonomic parasympathetic nervous system was the dominant division at the time of female subject sudden death. •No secretory glands, ducts, cavernous, spongiosum or erectile tissues were identified.
Maratos YK et al.39	France, Germany	2016	•MRI study •Observational, retrospective, single center •Consecutive women •MRI performed for clinical reasons •With or without vaginal gel opacification •Assumed Ostrzenski's previous papers as reference of the anatomical description of the G-spot	21	17-72	•“G-spot complex” present in the anterior vaginal wall in 62% (13/21) •10/10 cases in which gel opacification used •3/11 cases in the group in which gel was not used
Hoag N et al.40	Australia, Canada	2017	•Dissection of the anterior vaginal wall in cadavers •Section for macroscopic inspection (4.5x magnification) and histologic examination	13 (8 fixed and 5 fresh)	32-97	•No macroscopic structure other than the urethra and vaginal wall lining in the location of the putative G-spot •No erectile or “spongy” tissue in the anterior vaginal wall •In 1 specimen, a small amount of vascular tissue was noted in the subepithelial space •Systematic high density of veins in the lateral to the urethral and vaginal walls (number and thickness variable)
Mazloomdoost D et al.41	USA	2017	•En bloc removal of 4 female fresh-frozen cadaveric pelvises •18 to 25 serial sections obtained from each	4	67-97	•Epithelial, lamina propria, and muscular layer surrounded the urethral lumen in all specimens •Innervation and vasculature concentrated in the lamina propria •No differences in nerve distribution along the anterior vaginal wall •Differences in the innervation and vascularization along the urethra •No evidence of any structure corresponding to a possible G-spot described
Aydın S et al.42	Turkey	2020	•Specimens were taken from women with anterior vaginal wall prolapse undergoing colporrhaphy anterior repair •15 mm proximal to the external urethral orifice •Immunohistochemically stained: actin, smooth muscle Ab-1 and S100 Protein Ab-1 •Microvessels and nerves in the lamina propria and muscularis were counted in five consecutive high-power fields of a light microscope •Comparisons with proximal, distal, right and left paravaginal microvessel and nerve fiber density	17 •4 premenopausal •13 postmenopausal	33-70	•Vaginal nerve fibers in the lamina propria and muscularis have a fairly even distribution in the anterior vaginal wall •Vaginal small vessel vascularization and microvascularization also evenly distributed

EMG = electromyography; MRI = magnetic resonance imaging; PET-MRI = positron emission tomography–magnetic resonance imaging; PCOS = polycystic ovarian syndrome.