The dimensions and shape of the human vagina are of great importance in medicine and surgery; there appears to be no one way, however, to characterize the vagina's size and shape. In addition to variations in size and shape from individual to individual, a single woman's vagina can vary substantially in size and shape during sexual arousal and sexual intercourse. Parity is associated with a significant increase in the length of the vaginal fornix. The potential effect of parity may be via stretching and elongation of the birth canal at the time of vaginal birth.
Although the dimensions of the human vagina have not been the subject of intensive research to the same extent as research into human penis size, a number of research studies have been made of the dimensions of the human vagina.
Dimensions in the baseline state
Biggest vagina on the earth - Biggest vagina on the earth.
A 1996 study by Pendergrass et al., using vinyl polysiloxane castings taken from the vaginas of 39 Caucasian women, found the following ranges of dimensions:
- lengths (measured using rods): 6.9 to 15Â cm (2.7 to 5.9Â in);
- widths: 4.8 to 6.3Â cm (1.9 to 2.5Â in);
- introital diameters: 2.4 to 6.5Â cm (0.94 to 2.56Â in)
A second study by the same group showed significant variations in size and shape between the vaginas of women of different ethnic groups. Both studies showed a wide range of vaginal shapes, described by the researchers as "Parallel sided, conical, heart, [...] slug" and "pumpkin seed" shapes. Barnhart et al., however, weren't find any correlation amongst the race and the size of vagina. They were also unable to characterize the vaginal shape as a "heart, slug, pumpkin seed or parallel sides" as suggested by the previous studies. A 2003 study by the group of Pendergrass et al. also using castings as a measurement method, measured vaginal surface areas ranging from 66 to 107 cm2 (10.2 to 16.6 sq in) with a mean of 87 cm2 (13.5 sq in) and a standard deviation of 7.8 cm2 (1.21 sq in)
Research published in 2006 by Barnhart et al., gave the following mean dimensions, based on MRI scans of 28 women:
- Mean length from cervix to introitus: 6.3Â cm (2.5Â in).
- Mean width:
- at the proximal vagina: 3.3Â cm (1.3Â in);
- at the pelvic diaphragm: 2.7Â cm (1.1Â in);
- at the introitus: 2.6Â cm (1.0Â in)
Dimensions during sexual arousal
Lawrence, citing Masters and Johnson's Human Sexual Response (1966), states that pages 73 and 74 of that book show that typical vaginal depth in Masters and Johnson's participants ranged from 7â"8Â cm (2.8â"3.1Â in) in an unstimulated state, to 11â"12Â cm (4.3â"4.7Â in) during sexual arousal with a speculum in place.
Dimensions of medical devices used in the vagina
There does not appear to be large variation in the dimensions of the vagina within the same woman. Given the large range in the dimensions noted, it is most likely that one size for a vaginal device will not fit all vaginas.
Dimensions in pregnancy and childbirth
Dimensions of surgically created neovaginas
The depth of the typical neovagina created by male-to-female sex reassignment surgery is generally limited by the length of Denonvilliers' fascia, and is reported to be between 11 and 12Â cm (4.3-4.7Â in), within the range of the natural female vagina.
See also
- Vaginoplasty