ORIGINAL RESEARCH—ANATOMY/PHYSIOLOGY 3-D Volumetric and Vascular Analysis of the Urethrovaginal Space in Young Women With or Without Vaginal Orgasm Cesare Battaglia, MD, PhD,* Rossella Elena Nappi, MD, † Fulvia Mancini, MD, PhD, ‡ Stefania Alvisi, MS,* Simona Del Forno, MS,* Bruno Battaglia, MS,* and Stefano Venturoli, MD* *Department of Gynecology and Pathophysiology of Human Reproduction, Alma Mater Studiorum-University of Bologna, Via Massarenti, Bologna, Italy; † Research Centre for Reproductive Medicine, University of Pavia, Piazzale Golgi, Pavia, Italy; ‡ Department of Gynecology and Reproductive Medicine, Institut Universitari Dexeus, Barcelona, Spain DOI: 10.1111/j.1743-6109.2009.01650.x ABSTRACT Introduction. The existence of the G-spot is controversial. Aim. To evaluate, by the use of three-dimensional (3-D) ultrasonography, the anatomic structures of the ure- throvaginal space. Methods. Nineteen (Group I) eumenorrheic young women who experienced, and 20 (Group II) who did not experience a vaginal orgasm underwent two-dimensional (2-D) and 3-D ultrasonography and color Doppler analysis of the urethrovaginal space and of the clitoris during the early follicular phase of the menstrual cycle. Main Outcome Measures. 2-D ultrasonographic evaluation of the urethrovaginal space, and color Doppler evalu- ation of the urethrovaginal main feeding artery and dorsal clitoral arteries; 3-D volume calculation of the ure- throvaginal space, and 3-D power Doppler analysis of vascular indices of the urethrovaginal space and clitoral body (vascularization index, flow index, vascularization flow index); hormonal evaluation. Results. The 3-D reconstruction of the urethrovaginal space demonstrated a gland-like aspect with small feeding vessels. The total length (19.1  2.7 mm vs. 17.5  2.1 mm; P = 0.047), measured with 2-D ultrasound, and the 3-D mean volume (0.59  0.13 mL vs. 0.26  0.07 mL; P < 0.001) of the structures contained in the urethrovaginal space were significantly higher in Group I than in Group II. The mean time since the last intercourse was 31  9 hours in Group I and 18  3 hours (P = 0.033) in Group II. The urethrovaginal space vascularization, the clitoral volume and vascularization, and the circulating hormonal values did not significantly differ among the two groups. The mean volume of the structures contained in the urethrovaginal space was correlated with time since intercourse (r = 0.685; P = 0.021) and with serum testosterone (r = 0.637; P = 0.032) and androstenedione (r = 0.744; P = 0.011). Conclusions. The structures we observed in the urethrovaginal space have a gland-like aspect and their volume is correlated with both serum androgen concentrations and time since intercourse. Battaglia C, Nappi RE, Mancini F, Alvisi S, Forno S, Battaglia B, and Venturoli S. 3-D volumetric and vascular analysis of the urethrovaginal space in young women with or without vaginal orgasm. J Sex Med 2010;7:1445–1453. Key Words. Vaginal Orgasm; Female Prostate; G-Spot; Skene’s Glands; Doppler; Ultrasonography Introduction T he sexual response in women has been described as a four stage sequence (excitement/arousal, plateau, orgasm, and resolu- tion) that involves a successful integration of intact neural, vascular and muscular function; complex interactions between multiple neurotransmitter systems; and critical modulating influences from the endocrine system [1]. In addition to the above physiologic events, emotional, psychological, cul- tural, religious, and social factors may modulate the female sexuality. As a consequence, the overall importance of sex, the frequency of sexual inter- course, and the intensity or duration of sexual stimulation that is needed in order to be aroused 1445 © 2010 International Society for Sexual Medicine J Sex Med 2010;7:1445–1453