The Mechanics of the Vagina: Deformations, Tears, and Contractions

The vagina is a complex fibromuscular organ with walls that are usually collapsed against each other. The same walls can, however, stretch a great deal during important physiological functions such as conception, pregnancy, and delivery. The remarkable deformations of this organ have not been characterized, despite their impact on women’s health. In this talk, I will offer an overview of the research being conducted in my lab to quantify the unique mechanics and complex microstructure of the vagina by combining advanced experimental, theoretical, and computational methods. The vaginal tissue was found to experience very large and highly inhomogeneous deformations in both the passive (relaxed) and active (contracted) states. Over time, the vaginal walls deform very quickly when the loads are first applied and more slowly as the same loads are sustained, revealing their inherent viscoelasticity. Even in the presence of tears, the vagina can undergo large deformations with collagen fibers re-orienting to slow the propagation of tears. Higher contractions occur in the proximal (closer to the cervix) region than in the distal (closer to the introitus) region due to the smooth muscle fiber distribution within the organ. Future research will explore how mechanical and microstructural properties of the vagina are altered in pathological conditions such as sexual dysfunction, maternal trauma, and pelvic organ prolapse.