title: Menstrual cycle-related morphometric and vascular modifications of the clitoris.
abstract: BACKGROUND
  The evaluation of clitoral anatomy and function is of paramount importance to understand the physiology and pathology of clitoral function.
  
  
  OBJECTIVE
  To prospectively evaluate the clitoral volumetric and vascular modifications during the menstrual cycle, and analyze their relationship with circulating hormones and nitric oxide levels.
  
  
  METHODS
  Thirty healthy eumenorrheic women were studied in different phases of the menstrual cycle (day 3, 10, 14, 20, and 27). They were submitted to ultrasonographic (US) and Doppler analyses, and to hormonal and biochemical evaluations.
  
  
  METHODS
  Transvaginal US evaluation of uterus, ovaries, and clitoris; Doppler analysis of uterine and dorsal clitoral arteries; and measurement of plasma luteinizing hormone (LH), follicle stimulating hormone (FSH), estradiol, androstenedione, testosterone, and nitrites/nitrates concentration. Sex hormone binding globulin was assayed, and free androgen index was calculated.
  
  
  RESULTS
  During the menstrual cycle, FSH, LH, and estradiol changed as expected, whereas androgens did not show any significant change. The US assessment of the clitoral body volume evidenced a progressive increase with significant modifications during the periovulatory phase, after which it remained stable until day 20. Subsequently, the clitoral body volume decreased into the premenstrual phase (day 27), reaching values similar to those observed on cycle day 3. A comparable trend was observed in the nitrite/nitrate circulating values. The uterine and clitoral arteries presented significant modifications with reduced resistances in the periovulatory period. Estradiol levels resulted positively correlated with the clitoral body volume and inversely correlated with the dorsal clitoral artery pulsatility index (PI). Furthermore, the dorsal clitoral artery PI was inversely and significantly correlated with the nitrite/nitrate circulating values and the clitoral body volume.
  
  
  CONCLUSIONS
  Clitoral anatomic and vascular modifications are observable during the normal menstrual cycle.
authors.affiliation: Department of Obstetrics and Gynaecology, Alma Mater Studiorum-University of Bologna., Bologna, Italy. cesare.battaglia@unibo.it
authors.forename: Cesare
authors.initials: C
authors.lastname: Battaglia
authors.forename: Rossella Elena
authors.initials: RE
authors.lastname: Nappi
authors.forename: Fulvia
authors.initials: F
authors.lastname: Mancini
authors.forename: Arianna
authors.initials: A
authors.lastname: Cianciosi
authors.forename: Nicola
authors.initials: N
authors.lastname: Persico
authors.forename: Paolo
authors.initials: P
authors.lastname: Busacchi
authors.forename: Fabio
authors.initials: F
authors.lastname: Facchinetti
authors.forename: Domenico
authors.initials: D
authors.lastname: de Aloysio