[An updated overview on the anatomy and function of the female pelvic floor, with emphasis on the effect of vaginal delivery]

Abstract

Phylogenetically, the pelvic floor is a relatively old group of skeletal muscles which, along the acquisition of the erect posture by the human, gained a number of new important roles or were subjected to adaptation of some other roles performed earlier. The functional tasks of the pelvic floor in women (mostly of its prominent representatives - the levator ani muscles) include: supporting the contents of the abdominal cavity at the upright position, participation in the volitional and reflex compression of the urethra, narrowing the transverse dimension of the vagina and urogenital hiatus, involvement in sexual functions, and securing the terminal portion of the alimentary tract. The aim of this overview was to briefly review the information on the latest understanding of the anatomy of the pelvic floor, delineate its nomenclature recommended by the Federative Committee on Anatomical Terminology, and emphasize an array of physiological findings related to the contractility of these important muscles. The functional specialization of striated muscle fiber types and the anatomical basis of the relationship between vaginal delivery at term and postpartum urinary incontinence have been underlined. Nowadays, some intrapartum injuries to the pelvic floor can be successfully detected with ultrasound in the immediate postpartum period. This updated information should be part of a basic professional knowledge for obstetrician-gynecologist.