Is pelvic organ prolapse reversible?
More loaded than all that amasses atop the pelvic floor is the question of whether pelvic organ prolapse is "reversible". Many who ask this question aren't looking for a discussion of the biomechanics or healing potential of structures of the pelvic floor; they're looking for hope. We want to discuss this question, outlining the plausibility for various drivers of reduction in prolapse grade, provide insight into why we don't use the word "reverse", while also providing hope.
First, it might be helpful to consider the etiology of prolapse.
Pelvic organ support is provided by the interaction between the levator ani (LA) muscles and the connective tissues that attach the uterus and vagina to the pelvic sidewalls. The LA muscles provide lift and closure against downward forces. With damaged or weakened muscles, the hiatus increases, allowing an opportunity for descent of the pelvic organs. If the connective tissues are lengthened/lax, they can also fail to support the organs adequately. The architecture of the well-supported pelvic floor is a balanced system of pressures and load, and changes to the active and passive support structures can begin to challenge this balance.
It is worth noting that pelvic support changes throughout the day.
This is one reason that women are often advised to see their practitioner later in the day (note: this is not necessary but might be helpful for you if you're feeling like your care provider fails to see the extent of your POP during a morning session). The degree of descent can change depending on:
Pregnancy
The contents of the bowel/bladder
Recent physical activity
Hormonal composition
Stage in one's menstrual cycle
Time of day
Change in position
Effort given to a Valsalva event (how hard one bears down) or cough, as is often included in the assessment of POP
Conscious pelvic floor activation
Discrepancies in intra-rater reliability (differences in measurements by the same person)
Discrepancies in inter-rater reliability (when different people assessing do not share the same findings)
With the discussion of all of the factors that could lead to a change in the observed support of the pelvic floor, the question "how sure are we of what we see?" comes to mind. This also invites the discussion of how critical assigning a number to one's POP grade really is (we don't feel that it is worth nearly the weight it is often given) if the pelvic floor is constantly in flux, at least to some extent.
What could (potentially) result in a change in positioning, leading to a reduction of descent?
There are several factors that could influence the support of the pelvic floor (and this is where we start to get into the discussion of the potential of an observed reduction in grade).
Changes to the Size and Strength of the Levator Ani Muscles
Pelvic floor support is largely dependent on the function of the levator ani muscles. When these muscles weaken or are damaged, their ability to contract against downward forces is compromised. Over time, this can lead to POP. Improvements in muscle strength can improve the success of the muscles resisting the downward displacement of the pelvic organs. The goal of pelvic floor muscle training (PFMT) is to improve the tone of muscles/muscle groups, preparing them to be "ready" when called upon and includes the improvement of stiffness, strength, endurance, coordination, and function. These improvements in strength occur through greater neuromuscular efficiency (the ability of the nervous system to properly recruit the desired muscles to produce and reduce force) and muscular hypertrophy (the increase in volume and, therefore, mass). If the pelvic organs have descended as a result of weakened pelvic floor musculature, strengthening that musculature should, theoretically, offer greater pelvic floor support. It's not a leap to then suggest that improvements in active support structures could play a role in decreasing the downward displacement of pelvic organs to some extent. The question then becomes "to what extent?" and we'll get back to that a bit later. It's important to consider that much of what we know about muscular training is based on sports medicine literature that is, generally, discussing "normal" and well-functioning musculature. We know, however, that injury to the levator ani (particularly the puborectalis) muscles is common in those with POP.
Major levator injury (injury affecting more than half of the muscle bulk) is found in 16% of women with normal pelvic organ support but in between 34 and 55% of women with prolapse, thus proving the association between levator ani muscle injury and pelvic organ prolapse. (Delancey, 2017).
This major levator injury (avulsion) is associated with a 40% reduction in the force that the levator ani muscles can generate during a pelvic muscle contraction. If muscle damage that interferes with the capacity of the muscle to regain its strength has occurred, the pelvic floor might struggle with active support even after adopting a progressive and consistent strengthening program. Levator avulsion is also associated with an increase in the size of the genital hiatus (the opening of the pelvic floor), providing an increased opportunity for the contents of the pelvis to descend. Minor levator injuries evident at 3 months postpartum have been shown to improve over time. In one study, 62% of avulsions present at 3 months were no longer evident at 1 year postpartum (Delft et al. 2014). Partial avulsions had a tendency to improve over time, while complete avulsions were more persistent. Hypertrophy of the musculature that remains attached can occur over time, as well as hypertrophy and compensation of the surrounding musculature. After bilateral avulsion, for instance, hypertrophy of the iliococcygeus has been observed, "resulting in a levator shelf that is almost as strong as the original, just somewhat higher, and of course wider" (Dietz, 2010). Trauma in the body results in tissue remodeling, the process of reorganization or renovation of existing tissues. The tissue remodeling process could account for some of any observed change in the structures of the pelvic floor, including the musculature. Nearly 1/3 of women have been shown to have deinervation of the levator ani after first delivery but approximately 35% of that 1/3 recovered by 6 months postpartum (South et al., 2009). Denervation could result in changes to the function of the pelvic floor musculature and, in the event that reinnervation occurred, that function could be regained, accounting for a possible change in pelvic floor support by way of improved muscle function. There is little doubt that the function of the musculature of the pelvic floor plays a significant role in the development of pelvic organ prolapse. The million-dollar question then becomes:
Could improved coordination and hypertrophy of the muscles of the pelvic floor account for observed changes to the grade of prolapse?
The degree to which pelvic floor muscle strengthening could potentially influence the descent (or ascent) of the pelvic floor would depend on:
How great a change in muscle function/tone occurred It seems logical to suggest that a muscle that went from eliciting a reading of 0/5 to 5/5 might be more likely to be accompanied by a change (however slight) in pelvic floor support than a muscle that went from 0/5 to 1/5 to 4/5 to 5/5, for instance. A greater change in muscle tone/efficiency/strength would seem more likely during the postpartum recovery phase (the first few years postpartum) as changing demands and load placement/pressure distribution, shifts in hormonal composition, and tissue remodeling could potentially account for more rapid change
How much muscle strength contributed to the development of POP As we know, the development of POP is multifactorial and muscle strength is not the only factor that influences the development of prolapse. If the development of POP is related to connective tissue damage or strain beyond the musculature of the pelvic floor, it would seem plausible that muscle strengthening might not have as significant an effect on the presentation of prolapse.
How well the (better) functioning pelvic floor muscles can compensate While muscle damage is common, the ability to adapt and compensate for the decrease in function is one the most remarkable facets of the body. An improved compensation pattern (meaning, the surrounding musculature improves its ability to perform the role of the damaged or poorly functioning tissue) could lead to a change, over time, in the presentation of POP to some degree.
Changes to the Connective Tissue Supports of the Pelvic Floor
In addition to the more "active" support provided by the musculature, the pelvic floor also has a more "passive" support structure provided by the ligamentous and fascial structures. Damage to these structures can play a role in the development of POP. Whether the connective tissue or muscular structures are more at play in the development of POP is "like trying to decide which blade of a pair of scissors is the most important" (Delancey, 2016). Ligaments in those with prolapse are more lengthened than in those without prolapse. The cardinal ligament is 20% longer at rest in women with prolapse compared to women with normal support and, during Valsalva, it lengthens by 30 mm in women with prolapse compared to a 15 mm change observed in women without POP (Delancey, 2016). The bladder and urethra and the vagina and uterus are attached to the pelvic walls by a system of connective tissue called the endopelvic fascia. This fascial structure is one continuous sheath of fascia and is vulnerable to damage due to childbirth, repetitive straining, etc. How much can we influence the connective tissue supports of the pelvic floor? Some loading of the ligamentous and fascial structures will occur with muscular contraction, but their ability to adapt is much more limited than that of the muscles of the pelvic floor. In having less direct interaction with these more passive supports, it is less likely that efforts such as pelvic floor muscle training would result in a substantial or direct change to the connective tissue support structures. However, the prevention of further stretching of the ligamentous structures is worth noting: better functioning musculature, external support (with a pessary, for instance) and changes in demand could result in less strain being placed on the ligaments of the pelvic floor. An elongation under a constant load is resisted less over time (think of a rubber band that is holding something heavy for years; one can picture its ability to spring back as being compromised in this scenario) but developing greater support structures likely mitigates this effect, to some extent. Whether we are able to encounter change to what has already stretched/torn is much less likely.
Hormonal Composition
It is well established that there is a hormonal link in the presentation of pelvic organ prolapse. Estrogen receptors are present in the bladder, urethra, vagina, and pelvic floor musculature (Iosif, Batra & Astedt, 1981). Estrogen receptors play a role in controlling the breakdown and synthesis of collagen thereby aiding in the support mechanisms of the pelvis. A study evaluating preoperative use of topical estrogen in postmenopausal women found that 6 weeks of topical estrogen treatment increased synthesis of mature collagen, decreased degradative enzyme activity, and increased thickness of the vaginal wall (Rahn et al. 2014). The authors suggested that this intervention improves the maintenance of the intergrity of the pelvic floor's connective tissue. For the first several months following birth, women experience low levels of estrogen (which can continue for some for as long as they are breastfeeding). This hypoestrogenic state is associated with structural and functional changes in vaginal tissue, including atrophy of vaginal tissue, an upward shift in vaginal pH, decreased blood flow to tissues, shortening and narrowing of the vagina, and reduced vestibular sensation (Castelo-Branco, Cancelo, Villero J, et al. 2005; Mehta & Bachmann, 2008). A return to estrogen levels more similar to the pre-pregnancy state may account for tissue changes that lead to better support as time progresses in the postpartum period, and any estrogen supplementation might further support healthy tissues better able to withstand downward forces. How likely estrogen is to influence tissues of the pelvic floor in a woman who is not in a state of decreased estrogen is unknown.
Stage in One's Menstrual Cycle
One factor that influences the change of pelvic support could be the stage in one's menstrual cycle. Many notice that the days aligning with ovulation and/or the days leading up to menstruation are associated with changes in symptoms, and presentation of POP. This could be due to the role of hormones in menstruation and pelvic tissues, a change in the load/positioning of the uterus (however minor), changes in bowel habits, or other factors. If one is measured during a time of the month where more pelvic floor descent is typically present, a reading during another time of the month might reflect "normal" changes in support that occur throughout the month versus a true improvement (or worsening) of grade.
Changing Demands
The pelvic floor responds to what occurs above it. Changes in load and pressure influence the degree to which the pelvic floor must respond to adequately resist the forces placed on it. Changing the demand (in addition to bolstering the response of the pelvic floor through better strength, endurance, and coordination) could potentially result in a change in the architecture of the pelvic floor over time, or a more immediate change in the physical presentation. To discuss this further, let’s pinpoint the demands on the pelvic floor:
Pregnancy & Birth
Pregnancy is a factor leading to the change in the pelvic architecture and the function of the pelvic floor musculature. Changes in the hiatal area, vaginal location, bladder neck position, anal sphincter muscle thickness and levator ani volume can be identilfied with ultrasound and MRI in pregnant women (Betschart, Cornelia & Wisser, Josef; 2017). During pregnancy, the mechanical properties of connective tissues alter; fascia of a pregnant person stretches to a much greater degree before tissue failure occurs, but is also much weaker so that less stress is required to produce tissue failure (Landon, Crofts, Smith & Trowbridge; 1990). While some of the changes that occur to the pelvic floor are more transient, the opportunity for more lasting tissue damage is presented, particularly in the labor and birth process. Still, pregnancy is temporary and the loads placed upon the pelvic floor as a result of pregnancy will undoubtedly shift after birth. A significant degree of healing (which we would describe as a combination of wound healing, reinnervation, hypertrophy, compensation, hormonal changes) occurs in the postpartum chapter. It would make sense that the presentation of prolapse would shift slightly in the postnatal period in relation to all of the substantial changes that occur during this time. Again, whether this means the pelvic floor support "reverses" itself to a state identified prenatally is what we are interested in discussing.
Constant Straining (Constipation/Chronic Cough)
Chronic constipation and cough are two risk factors for the development of POP. Constipation can increase the load placed upon the pelvic floor structures and the subsequent straining that can occur during defecation further increases the pressure placed on the pelvic floor. Those with POP often notice changes in support related to whether their bowels are full or empty and so it is not a stretch to suggest that the efficiency of the gut could influence the positioning of the pelvic organs. Additionally, excess gas/bloating could have a deleterious impact on pelvic floor support, and measures to reduce the gastrointestinal distress could result in a change demonstrated in the support of the pelvic floor. Coughing is an activity associated with high readings of intra-abdominal pressure and the pelvic floor is tasked with the role of resisting these large influxes in pressure. Learning to better manage constipation and chronic cough could have a significant influence on the symptoms, and possibly the presentation of prolapse.
Changes in Pressure Management/Load Distribution
As we've mentioned, the pelvic floor is subjected to the pressure and forces from above. A focus entirely on the pelvic floor (strength/endurance, etc.) is unlikely to result in the best management of prolapse because it fails to consider the impact of pressure, muscular recruitment, and load beyond the pelvic floor. Research has identified ranges in intra-abdominal pressure among different participants performing the same task (Shaw et al., 2014). Research has also shown ranges of intra-abdominal pressure for different versions of a task being performed by the same person and that factors, such as breath, can influence the generation of intra-abdominal pressure (Gerten, 2008; Hagins et al. 2004). Additionally, muscle recruitment of the trunk influences the generation of IAP (Arjmand & Shirazi-Adi, 2005). From this, we could deduce that it is likely we have direct influence on the generation of intra-abdominal pressure and could therefore modulate it to some degree. If a person has a history of performing movements and tasks in a "high pressure" strategy (that is, they generate high levels of IAP - perhaps greater than what might be needed to address the demand) and they learn to accomplish the same tasks with a lower pressure strategy, it seems a logical hypothesis that their pelvic floor would have less to resist which could influence its ability to ascend.
Changes in Weight
Large body size is identified as a risk factor for the development of pelvic organ prolapse. The most likely mechanism for this is an increase in weight leading to increases in intra-abdominal pressure. Weight loss ( by way of bariatric surgery) has been suggested to lessen symptoms of pelvic organ prolapse but does not seem to lead to a reduction in grade (Lee, Kerkhof, van Leijsen & Heesakkers, 2017).
Shifting Demands of Physical Activity
Many notice the initial development, or a worsening of observed POP in the early postpartum period. This chapter is often associated with repetitive motion (taking a baby in and out of a crib, carrying a carseat, carrying small children) that might exceed the level of physical activity that a woman had trained previously. Additionally, this activity might be occurring on a more-vulnerable pelvic floor that is still in the early stages of recovery from pregnancy/birth and so the impact of the activity might imply even greater demands on the pelvic floor. These demands are likely to shift as time goes on: babies eventually walk (for the most part) and require less carrying, they are able to perform more tasks themselves, the mother might receive more physical assistance in managing these tasks (a return to work), etc. The accompanying demand on the pelvic floor might lessen and, in conjunction with regaining strength and function, the result might be a pelvic floor that is appears less challenged in its support.
Efficiency of the Body as a Whole
High-demand activities are associated with relative higher pressures; increases in intra-abdominal pressure are largely accomplished by activity of the transversus abdominis which increases stabilization of the trunk and reduces compression forces in the lumbar spine. Consider the demand of basic activities like getting up off the couch or picking up a child in a carseat. In an untrained individual, the relative difficulty is likely much higher than it would be in a trained individual. Think of an untrained person getting out of a chair: they're likely to grunt, hold their breath, hoist themselves out of the chair. They are creating more intra-abdominal pressure to accomplish the task. A trained individual could likely bring themselves out of the same chair while holding a conversation, breathing, and with control. Less of an influx in intra-abdominal pressure is required (or, perhaps, better management of it is demonstrated). Strengthening the body (in a way that did not compromise pelvic floor support) would, theoretically, present less of a challenge to the pelvic floor support system as a result of the greater efficiency with which one could move. The relative difficulty of tasks would lessen and the pressure associated with accomplishing them would, hypothetically, lessen. Additionally, it has been noted that co-activation of the pelvic floor muscles occurs with the abdominal musculature and the rotators of the hip (Sapsford et al. 2000; Tuttle et al. 2016). It is proposed that strengthening structures near the pelvic floor could aid in the strengthening of the pelvic floor musculature, as well. Gains in strength, endurance, and efficiency in muscles near and more distal to the pelvic floor could play an indirect and more direct role in addressing pelvic floor muscle strength deficits.
Factors Potentially Impacting the Validity of Pelvic Floor Assessment
Time of Day
Many find their symptoms and the observed descent of their POP to be worse as the day progresses. Assuming a person spends a fairly significant portion of their day upright, we can reasonably assume these changes to be associated with the demands placed on the pelvic floor by gravity throughout the day. An observation of POP in the morning, after a night spent in a horizontal position might not demonstrate the impact of gravity after a long day in more of an upright stance.
Change in Lumbopelvic Positioning
Research has identified that lumbopelvic positioning can impact the activation patterns of the pelvic floor (Capson, 2011). Changes in activation patterns by way of changes in lumbopelvic positioning could influence muscle strength and support efforts over time and better closure and lift against downward displacement in the more immediate term. Changing the pelvic position also changes the distribution of load on the pelvic floor, the axis of the vagina, and the support from bony structures leading to immediately evident changes in the positioning of the pelvic organs. You can test this yourself with the use of a hand mirror: view the Introitus in a supine position with a posteriorly tilted pelvis, "neutral" pelvis, and an anteriorly tilted pelvis. While it will be more obvious to some, most will notice at least subtle changes in the appearance of one's anatomy. You can also play around with this with tactile feedback from a finger or two: if you inserted a finger, you can feel the change in the vaginal axis. As the vagina moves from a more-horizontal to a more-vertical position, you'll notice that your perception of the descent of the pelvic organs can change, as well. These changes could account for some of the observed differences in pelvic floor anatomy, especially visually.
Conscious Activation of the Pelvic Floor Muscles & Changes in Effort in Valsalva/Coughing
One of the main goals of pelvic floor muscle training involves teaching the pelvic floor to better respond the influxes in pressure. It is possible (and preferable!) that this training effect could impact the downward displacement of the pelvic organs during a cough or a voluntary bearing down effort (as is often requested to assess for prolapse). Lessening of downward movement would indicate (potentially) better support of the pelvic floor. This levator coactivation during Valsalva could occur either voluntarily or involuntarily; relaxing the pelvic floor during Valsalva can feel threatening as it may accompany a loss of urine, stool, or gas. The activation of the levator ani would impede full appreciation of the downward descent of the pelvic organs. Additionally, awareness of bearing down (and its negative implications on pelvic floor support) could increase, leading someone to be less likely to perform a max effort (the opposite could be true, as well). This might result in the appearance of less movement. It is generally recommended that a Valsalva effort be carried out for >6 seconds to increase the likelihood of fully appreciating the downward movement of the pelvic organs.
Changes in Intra- and Inter-Rater Reliability
Efforts have been made to better quantify the support of the pelvic floor to lessen the discrepancies between readings and provide a more objective assessment. One such effort is the implementation of the POP-Q system which includes specific points of measure. The POP-Q system has been found to be a reliable tool for quantifying measurements of pelvic support. Not all practitioners employ use of the POP-Q system (and might instead employ different assessment measures) and the possibility for a challenge to reliability exists. A consensus on POP grading and what "normal" support in the pelvic floor is has yet to be fully reached. For instance, following menopause, a degree of prolapse is considered virtually ubiquitous. Many consider a grade 1 (sometimes 2) to be a "normal" finding in the parous woman. Seeing a practitioner who regards a grade 1-2 POP as "normal" will likely result in a much different conversation that seeing a practitioner who considers "normal" support to be a grade 0. The subjective nature of assessments and the way various practitioners discuss support of the pelvic floor can lead to much confusion and frustration. It is not uncommon to receive seemingly contradictory results from different practitioners within a short time frame. Some of this could be due to the factors involved in daily support changes, while we could also attribute these discrepancies to a lack of consensus in defining POP.
What Does the Research Say About Changes in Grade in POP?
A 2010 study conducted by Brækken et al. sought to understand the role that pelvic floor muscle training might play in reduction of grade. Both the intervention and control groups received lifestyle advice and learned "the Knack". The intervention group also received instructions to perform 8-12 close-to-maximum contractions per day and attended once weekly physical therapy sessions in the first three months and a session every other week for the second 3-month period. Nineteen percent of the women in the intervention group experienced a reduction of 1 stage in POP-Q measurements while 8% of the control group experienced a reduction of 1 stage. In addition to degree of support, PFMT was found to lessen the bother of symptoms. The authors cautioned, however, that the results might not be generalizable to more significant grades of POP. The POPPY trial is a multi-center randomized controlled trial that explored the impact of individualized pelvic floor muscle training on pelvic organ prolapse symptoms (Hagen et al. 2014). In addition to describing the influence on perception of symptoms, they also discuss the changes in pelvic floor support at 6 months compared to baseline measurements. In the intervention group, an increase of POP by 2 stages was noted in 2% of the participants versus 5% of the controls. An increase in 1 stage was noted by 16% of the intervention group compared to 17% of the control group. No change was identified in 55% of the intervention group compared to 58% of the control group. A reduction by 1 stage was noted in 20% of the intervention group and 15% of the control group. Finally, a reduction of 2 stages was noted in 7% of the intervention group compared to 5% of the control group. While a greater proportion of women in the intervention group had an improvement in prolapse stage by 6 months, this difference did not reach statistical significance. A study evaluating the natural progression POP over the course of 5 years demonstrated that 47% had an unchanged POP-Q stage, 40% showed regression, and 13% showed progression (Miedel et al., 2011). The research cited above suggests that an improvement in the stage of prolapse is a potential option for some. In the Brækken (2010) study, 19% experienced a reduction in grade. A more impressive 74% reported a reduction in bothersome symptoms. We have discussed in prior blogs (and in our course, POP UP: An Uplifting Guide) that symptom-reduction is not dependent on grade and this research suggests this, as well.
"Reversal"
We can demonstrate the many ways in which pelvic floor support might be aided and improve and we have provided evidence to suggest this finding in a percentage of people. But does this mean that pelvic organ prolapse is "reversing"? The word "reverse" means to move backward, or to make something the opposite of what it was. It implies that the factors that led to POP have been reversed, eliminated. It implies rewinding clocks and undoing events that cannot be undone. While it might just seem a quibbling over semantics to some, we do not propose prolapse "reversal" as an outcome we feel comfortable endorsing. We propose that it is possible to regain function and rebuild strength. We suggest that it is achievable to redistribute pressure and load. We recognize a shift in the reliance on certain structures to others (the incredible ability to compensate and adapt). We anticipate some change due to reinnervation, the remodeling of tissue, and the replenishing of estrogen. We acknowledge that a reduction in POP stage can be observed in a percentage of people. We see these steps as a direction forward, not back. As such, we have made the intentional decision to abstain from referring to changes in pelvic floor support as a “reversal” of prolapse. We believe that reduction or “reversal” is not a prerequisite of moving forward with POP. Shifting our focus from the outcome of grade reduction (which has yet to be demonstrated as a reality for the majority) to the actionable steps that one can take to better manage POP feels empowering, pragmatic, and supported-by-evidence. The steps are the same and the recommendations for POP management are in line with what one would propose for eliciting a change in stage, but our intention is not narrowly defined by the structure itself. We control what we can.
To be clear, we do not fault those who wish that they could fully eliminate the presence of prolapse, reversing time and trauma. We understand that choosing to shift focus away from discussing treatment of prolapse as “reversing” prolapse means, at least in some way, that we are acknowledging that that might not be possible. In doing so, we are finding some level of acceptance, a journey in which we wholeheartedly believe but know that not everyone does. We believe that the journey to better POP management favors finding acceptance and moving forward with support (in the pelvic floor and otherwise!) over seeking to “reverse” what might not be (at least fully) reversible.
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