Talk:Vagina Development

Background Reading

Mullerian ducts

• The development of the human vagina. BULMER D. J Anat. 1957 Oct;91(4):490-509. No abstract available. PMID: 13475148 | PMCID: 1244904

• New concepts on the development of the vagina. Shapiro E, Huang H, Wu XR. Adv Exp Med Biol. 2004;545:173-85. Review. No abstract available. PMID: 15086027

• Revisiting old vaginal topics: conversion of the Müllerian vagina and origin of the "sinus" vagina. Cai Y. Int J Dev Biol. 2009;53(7):925-34. Review. PMID: 19598112 | IJDB

"Vaginal development has been a longstanding controversy, which hampers studies on vaginal diseases as well as cervical and uterine diseases. Most concerns center on: why is the vaginal epithelium different from the uterine epithelium; and where does the vagina originate from? It is commonly held that the rodent vagina has a dual origin: the cranial part is derived from the Mullerian duct (Mullerian vagina) and the caudal part derived from the urogenital sinus (sinus vagina). This concept was deduced from morphological observations. However, it cannot explain the difference between the Mullerian vagina and the uterus. Moreover, accumulating new data from genetic and molecular studies contradicts the urogenital sinus origin of the sinus vagina. The present review summarizes previous morphological observations and new findings from genetic and molecular studies, and addresses molecular mechanisms underlying the origin and organogenesis of the vagina in rodents. It provides evidence to show that the whole vagina is derived the Mullerian duct. BMP4 reshapes the intermediate mesoderm-derived Mullerian duct into the vaginal primordium. The latter thus exhibits different features from the uterus, including the stratified squamous epithelium and insensitivity to anti-Mullerian hormone. The sinus vagina is formed by extrinsic BMP4-mediated caudal extension of the Mullerian duct. The present review thus shows how a century of controversy over the origin and organogenesis of the vagina has been resolved. This new understanding will provide additional insight into genetic diseases and tumors of the female reproductive tract."

• Fetal development of the female external urinary sphincter complex: an anatomical and histological study. Sebe P, Fritsch H, Oswald J, Schwentner C, Lunacek A, Bartsch G, Radmayr C. J Urol. 2005 May;173(5):1738-42; discussion 1742. PMID: 15821572

• Helper function of the Wolffian ducts and role of androgens in the development of the vagina. Drews U. Sex Dev. 2007;1(2):100-10. PMID: 18391520

"Here experiments with the complete androgen receptor defect in the testicular feminisation (Tfm) mouse are reported which show that the vagina is formed by caudal migration of Wolffian and Müllerian ducts. The cranial ends of the Wolffian ducts successively regress while the Müllerian ducts fuse to form the vagina. Immunohistochemistry of the androgen receptor reveals that the caudal ends of the Wolffian ducts remain in the indifferent stage and therefore have been mistaken as sinuvaginal bulbs. The Wolffian ducts do not contribute to the vagina itself but have a helper function during downward movement of the vaginal bud in the female. In the male the caudal ends serve as androgen operated switch for the negative control of vaginal development. The results indicate that the rudimentary vagina in the complete androgen insensitivity syndrome (CAIS) corresponds to non obliterated caudal ends of the Müllerian ducts. Selective atresia of the vagina in the MRKH (Mayer-Rokitansky-Kuster-Hauser) syndrome may be explained by the failure of Wolffian and Müllerian ducts to descend caudally"

• Lifetime changes in the vulva and vagina. Farage M, Maibach H. Arch Gynecol Obstet. 2006 Jan;273(4):195-202. Epub 2005 Oct 6. Review. PMID: 16208476

"The morphology and physiology of the vulva and vagina change over a lifetime. The most salient changes are linked to puberty, the menstrual cycle, pregnancy, and menopause. The cutaneous epithelia of the mons pubis, labia, and clitoris originate from the embryonic ectoderm and exhibit a keratinized, stratified structure similar to the skin at other sites. The mucosa of the vulvar vestibule, which originates from the embryonic endoderm, is non-keratinized. The vagina, derived from the embryonic mesoderm, is responsive to estrogen cycling. At birth, the vulva and vagina exhibit the effects of residual maternal estrogens. During puberty, the vulva and vagina acquire mature characteristics in a sequential fashion in response to adrenal and gonadal maturation. A trend to earlier pubertal onset has been observed in Western developed countries. In women of reproductive age, the vaginal mucosa responds to steroid hormone cycling, exhibiting maximal thickness and intracellular glycogen content at mid-cycle. Vulvar skin thickness remains unchanged but menstrual cycle-associated changes in ortho- and parakeratosis occur at the cytological level. The vulva and vagina further adapt to the needs of pregnancy and delivery. After menopause, tissue atrophy ensues. Post-menopausal changes in skin barrier function, skin hydration, and irritant susceptibility have been observed on exposed skin but not on the vulva. Nevertheless, older women with incontinence are at increased risk for developing incontinence dermatitis. A combination of factors, such as tissue atrophy, slower dissipation of excess skin hydration, shear forces associated with limited mobility, and lower tissue regeneration capacity increase the risk of morbidity from incontinence dermatitis in older women."

Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome

text and table below from http://www.ojrd.com/content/2/1/13

Surgical creation of a neovagina A number of techniques are appropriate for the correction of vaginal agenesis and there is no consensus regarding the best option, the approach being most often based on the surgeon's experience. Three methods are currently in use:

- The Abbe-McIndoe operation: this involves the dissection of a space between the rectum and the bladder, placement of a mold covered with a skin graft into the space, and diligent postoperative vaginal dilatation. Modifications of this procedure rely on spontaneous epithelialization or on the use of different materials such as peritoneum [111], minora labia grafting, or synthetic materials [112,113].

- The Vecchietti operation is a mixture of surgical and nonsurgical methods. It has been performed frequently in Europe over the last 20 years [70]. This procedure involves the creation of a neovagina via dilatation with a traction device attached to the abdomen, sutures placed subperitoneally by laparotomy, and a plastic olive placed in the vaginal dimple. A laparoscopic or celioscopic modification is often preferred and leads to comparable results [114].

- Sigmoidal colpoplasty: this technique involves vaginal replacement or creation of a neovagina by grafting a 12–18 cm long segment of sigmoid [115], providing that a single and/or left pelvic kidney does not impair the procedure. Sigmoidal colpoplasty is believed to be an efficient procedure giving excellent results, although complete adequacy for coital function often requires prolonged care and support [116].

Summary of differential diagnosis between MRKH syndrome and isolated vaginal atresia, WNT4 syndrome, and androgen insensitivity syndrome.
	MRKH/MURCS	Isolated vaginal atresia	WNT4 syndrome	Androgen insensitivity
Upper vagina	Absent	Variable	Absent	Absent
Uterus	Absent	Present	Absent	Absent
Gonads	Ovary	Ovary	Masculinized ovary	Testis
Breast development	Normal	Normal	Normal	Normal
Pubic-hair development	Normal	Normal	Normal	Sparse
Hyperandrogenism	No	No	Yes	No
Karyotype	46, XX	46, XX	46, XX	46, XY
Morcel et al. Orphanet Journal of Rare Diseases 2007 2:13   doi:10.1186/1750-1172-2-13

Baseline dimensions of the human vagina. Barnhart KT, Izquierdo A, Pretorius ES, Shera DM, Shabbout M, Shaunik A. Hum Reprod. 2006 Jun;21(6):1618-22. Epub 2006 Feb 14. PMID: 16478763

magnetic resonance imaging (MRI) to quantify distribution of a vaginal gel. Seventy-seven MRI scans were performed on 28 women before gel application to establish baseline vaginal measurements. Average dimensions were calculated for each woman and for the population. The influence of potential covariates (age, height, weight and parity) on these dimensions was assessed. ...Mean vaginal length from cervix to introitus was 62.7 mm. Vaginal width was largest in the proximal vagina (32.5 mm), decreased as it passed through the pelvic diaphragm (27.8 mm) and smallest at the introitus (26.2 mm)."

Complex malformations of the female genital tract. New types and revision of classification. Acién P, Acién M, Sánchez-Ferrer M. Hum Reprod. 2004 Oct;19(10):2377-84. Epub 2004 Aug 27. PMID: 15333604