Graphic integration of causal factors of pelvic floor disorders: an integrated life span model

Abstract

There is growing interest in causal factors for pelvic floor disorders. These conditions include pelvic organ prolapse and urinary and fecal incontinence and are affected by a myriad of factors that increase occurrence of symptomatic disease. Unraveling the complex causal network of genetic factors, birth-induced injury, connective tissue aging, lifestyle and comorbid factors is challenging. We describe a graphical tool to integrate the factors affecting pelvic floor disorders. It plots pelvic floor function in 3 major life phases: (1) development of functional reserve during an individual's growth, (2) variations in the amount of injury and potential recovery that occur during and after vaginal birth, and (3) deterioration that occurs with advancing age. This graphical tool accounts for changes in different phases to be integrated to form a disease model to help assess the overlap of different causal factors.

Figure 1. Integrated lifespan analysis of pelvic floor function

This graphical display of the abstract concept of pelvic floor function tracks the functional reserve throughout different phases of a woman’s lifespan. Initially, pelvic floor structure growth in late teens leads to a fully developed pelvic floor. Vaginal birth affects pelvic floor function. Finally, age-related deterioration occurs until a symptom threshold is reached where the functional reserve present earlier in life is lost. (© DeLancey 2007)

Figure 2. Phase I Variation in Growth and Development

Differences in the degree of functional reserve development during early life, and the effect it can have on when symptoms may develop are demonstrated. An individual with more functional reserve (A) may not develop symptoms during her lifespan while somewhat less reserve may lead to symptoms late in life and even less reserve, symptoms early in life. (© DeLancey 2007)

Figure 3. Variations in Birth Damage and Repair

Different degrees of functional impairment after vaginal birth are shown. A delivery that does not permanently injure any structure beyond the body’s ability for repair (A) may not affect an individual’s development of symptoms later in life. A more significant injury (B) that is partially healed may decrease functional reserve leading to earlier occurrence of symptoms. Severe injury (C) may cause immediate problems that cannot be repaired, leading to symptomatic disease following birth that does not resolve. A second birth may further affect the rate of decline, depending again on degree of cumulative injury. (© DeLancey 2007)

Figure 4. Accelerated Deterioration

Several factors may affect the rate at which pelvic floor function deteriorates. Genetic factors that affect rates of connective tissue and muscle aging, and changes that are influenced by an individual’s activity level or nutritional factors (illustrated by the B curve in the graphic) are a few examples. (© DeLancey 2007)

Figure 5. Lifestyle Impact

The stresses placed on the pelvic floor vary from one individual to another. For example, a sedentary individual may never have stress incontinence where one that participates in high-impact aerobics may develop this condition. Thus, two women having the same functional capacity may reach symptoms earlier or later depending on variance in threshold of activities (B activity line versus A activity line in the graphic). (© DeLancey 2007)