Learning Objectives:After participating in this continuing professional development activity, the provider should be better able to:
1. Identify stress urinary incontinence in women of childbearing age.
2. Explain the risk factors, epidemiology and natural history of stress urinary incontinence as they relate to patient age and future childbearing intentions.
3. Develop evidence-based management counseling and conservative treatment recommendations and describe indications for subspecialty referral, when needed.
Stress urinary incontinence (SUI) is the involuntary loss of urine with activity, such as cough, sneeze, or physical exertion, and is generally thought to arise from weakened connective tissue and muscular support to the urethra.1 Although its reported prevalence varies widely based on the definition used, well-designed population-based studies have found that approximately one-third of women experience symptoms of SUI.2 SUI prevalence has clearly been shown to increase with age and parity, but a recent systematic review suggested that even among young nulliparous patients, UI is quite prevalent (20.1%) with the dominant subtype being SUI (up to 79%).3 UI becomes even more prevalent in the antenatal and immediate postpartum periods, with up to 65% of women reporting symptoms. Traditionally, women are counseled that SUI arising in the postpartum period will resolve and long-term follow-up studies have shown that most incontinence does improve by 12 months postpartum. However, the improvement seems transient as demonstrated in 2 studies that showed that among women who reported SUI at 3 months postpartum, 73% and 92% reported bothersome SUI symptoms 5 to 6 years later.4,5
SUI in young women who may desire future fertility presents a unique clinical challenge as many treatments, particularly surgery, have historically been withheld until childbearing is complete due to a lack of data regarding safety and efficacy in future pregnancy and/or delivery.
Given the high prevalence of disease, it is very likely that specialists in obstetrics and gynecology will encounter young women with SUI. As such, we aim to provide obstetrician/gynecologists with the tools needed to effectively diagnose, counsel, and treat SUI in women who may not have completed childbearing. We will review, with a focus on women of childbearing age, known modifiable risk factors and options for conservative management that obstetrician/gynecologists can safely begin at the time of diagnosis. We will also review the current evidence regarding surgical management of SUI in young women so that obstetrician/gynecologists can provide evidence-based counseling and appropriate subspecialty referral to patients for whom conservative management has failed to control their SUI symptoms. When available, guidelines from national societies are included for reference.
Diagnosis of SUI
The diagnosis of SUI can be obtained from a detailed history and physical examination, a urinalysis to rule out a urinary tract infection (UTI), a supine cough stress test (ideally with a full bladder), and a postvoid residual (PVR) volume.6 While assessing the likelihood of SUI on history, important points to elicit are whether the patient leaks urine with activity or abdominal strain, such as with cough, sneeze, laugh, heavy lifting, or exercise. Validated questionnaires have been developed to help decipher types of incontinence if the history is not clear.7
If the patient affirms symptoms of SUI, it is important to establish and document baseline symptom severity to assess response to future interventions. Symptom severity can be assessed and documented by eliciting number of sanitary pads required per day, the volume of leakage, number of leakage episodes per day or week, and the impact on quality of life, particularly work productivity, social connections, and intimacy.
A standard gynecologic examination is necessary to rule out rare anatomic findings that could mimic SUI, such as a urethral diverticulum or urogenital fistula.8 A supine cough stress test is performed in lithotomy position as the gynecologist spreads the labia and asks the patient to cough with vigor. If urine escapes the urethra simultaneously with cough, this is considered a positive cough stress test and confirms the diagnosis of SUI. A negative supine cough stress test does not rule out SUI, as some women experience leakage with very specific triggers. Standing cough stress test may be advised, as some young women are able to compensate with strong levator muscle contraction in the supine position.
A urinalysis should be performed in the same visit to confirm that these findings are not secondary to an active UTI and to rule out microscopic hematuria that may require further investigation.6 When patients and physicians are unsure whether the apparent leakage is urine and not vaginal discharge, a phenazopyridine pad test can be used to confirm a urinary source. Phenazopyridine is a bladder analgesic often prescribed for bladder discomfort and turns the urine bright orange while the medication is being excreted. Taking advantage of this medication property, the test involves the patient consuming 2 to 3 tablets of phenazopyridine 100 mg or 200 mg by mouth per day for 2 to 3 days while wearing a pad or panty liner. An orange stain on the pad confirms a urinary source of leakage, whereas wetness that is not stained orange during this test suggests a nonurinary source such as vaginal discharge or sweat.
Nonsurgical/Conservative Interventions
Modifying Risk Factors
Weight Loss
Higher body mass index (BMI) is known to contribute to SUI incidence and severity. As such, the impact of weight loss on UI was evaluated in a well-designed, multi-institutional randomized controlled trial (RCT), which demonstrated that among women with a BMI of 25 kg/m2 or more, even a modest 5% to 10% reduction in body weight resulted in a mean 57% reduction in stress incontinence episodes.9 Further reinforcing the beneficial impact of weight loss on SUI is the growing body of literature reporting SUI outcomes after weight loss surgery. A systematic review on the topic reported a pooled SUI cure rate of 55% [95% confidence interval (CI): 40%-70%] after bariatric surgery and its associated weight loss.10 Therefore, The American College of Obstetricians and Gynecologists (ACOG) and the American Urogynecologic Society (AUGS) support weight loss as a means to significantly improve SUI symptoms in overweight and obese women.6
Smoking Cessation
Cigarette smoking is known to cause connective tissue damage through its deleterious effects on collagen and may result in weakened urethral support, thereby contributing to SUI. However, data regarding the association between smoking and SUI are mixed and the impact of smoking cessation on SUI has not been studied. Ultimately, smoking cessation should be strongly encouraged for its other health benefits and because it may be beneficial for SUI, particularly if accomplished in conjunction with other SUI treatment modalities.
Pelvic Floor Muscle Training
The goal of pelvic floor muscle training (PFMT), colloquially referred to as Kegel exercises, is to improve the pelvic floor muscle strength, endurance, power, and relaxation, or a combination of those parameters. PFMT has been adopted as a mainstay of prevention and conservative treatment of SUI. According to a Cochrane Database Systematic Review evaluating the effect of PFMT on SUI, women who underwent some form of PFMT were 8 times more likely to report cure of symptoms than controls (56% vs 6%, RR: 8.38, 95% CI: 3.68-19.07).11 PFMT regimens varied but were commonly described as Kegel contractions of maximum intensity held for several seconds, in sets of 6 to 10 contractions, with multiple sets per session. Typically, the initial session was taught by a provider and confirmed by physical examination. Subsequent classes were in the clinic and/or at home. As such, ACOG and AUGS recommend PFMT alone or in combination with adjunct treatments such as biofeedback (BF), pelvic floor electrostimulation (PFES), or weight loss as first-line therapy for SUI.6
Compared with nulliparous controls, primiparous women are significantly more likely to experience SUI, even at 12 months postpartum [odds ratio (OR): 2.4 (95% CI: 1.6-3.7)].12 As such, PFMT initiated in the postpartum period has been investigated as an opportunity to prevent or treat SUI. In one study evaluating the effect of a comprehensive care intervention starting 1 week postpartum, which included PFMT, psychologic support, supervision, and education, rates of SUI were halved (31.7% vs 15.0%, P = 0.002) compared with no intervention.13 A systematic review concluded that initiating PFMT within 12 months postpartum was associated with half as many women reporting SUI at 12 months postpartum than those who underwent no intervention [RR: 0.47 (95% CI: 0.23-0.97)].14 Overall, studies would suggest that initiating PFMT as early as 1 week postpartum can result in decreased SUI, and that these results may be sustained at 12 months. Although there are no guidelines to date, it is reasonable to recommend PFMT to postpartum patients for the prevention and management of SUI, given the overall safety and efficacy of the intervention.
Home PFMT Versus Supervised PFMT
Currently, the data are mixed regarding the benefit of supervised PFMT over home regimens. In one 5-year study assessing differences in supervised compared with home PFMT, objective urinary leakage improved significantly in both groups; no between-group difference in degree of improvement was noted. These findings suggest that home exercises are equally effective as compared with supervised sessions.15 This study also highlighted a major limitation of PFMT in the management of SUI by reporting that long-term adherence to PFMT was poor in both groups with only 19% reporting regular supervised PFMT sessions and 6% of patients reporting continued regular home PFMT after 12 months. In contrast, an RCT comparing supervised to home PFMT found objective cure rates to be higher in the supervised PFMT group [62% vs 28%, respectively, OR: 4.0 (95% CI: 1.4-11.0; P = 0.011)].16 Therefore, it remains unclear whether supervised PFMT is superior to home PFMT, and it may be highly dependent on the training and expertise of the physical therapist and their protocol for management of SUI. Thus, patient preference, likelihood of adherence to either approach, insurance coverage, and availability for frequent supervised physical therapy visits may help guide the decision of where to carry out PFMTs.
Home PFMT-Smartphone Applications
With the increasing use of smartphones, home PFMT applications are becoming widely available for the treatment of SUI and may be a safe, effective way to improve compliance with PFMT for patients who do not have access to, or prefer not to work with a pelvic floor physical therapist. In one study of women with an average age of 44 years who were randomized to use of a smartphone-based PFMT app (Tat, Umea, Sweden) or no intervention over 3 months, weekly incontinence episodes were reduced from 21 (10.5-28.0) to 7 (0-14) in the app group. Notably, the control group also decreased slightly from 17.5 (10.5-24.5) to 14 (7-26).17 There was also a significant improvement in symptom severity in both the app and control groups and in symptom-specific quality of life in the app cohort. Overall, 66.7% of app users were satisfied with their treatment. Numerous other pelvic floor strengthening apps are available for both iPhone and Android and may be helpful for busy women who need flexibility in their schedule while trying to adhere to a PFMT regimen.
Biofeedback
BF is use of an instrument to evaluate the strength and duration of a pelvic floor contraction and to communicate that information to the patient. Traditionally, BF is offered by physical therapists as an adjunct to a supervised PFMT regimen. In addition, numerous pelvic floor BF devices designed for at-home use have recently come onto the market with limited data as to their efficacy. A Cochrane systematic review concluded that there may be a slight benefit to adding BF to supervised PFMT, but that this benefit may be related to differences in treatment protocols and number of interactions with clinicians rather than BF itself.18 ACOG and AUGS state that PFMT is effective alone or in combination with BF and make no statement about the safety or efficacy of devices designed for at-home use.6
Pelvic Floor Electrostimulation
A Cochrane Database Systematic Review evaluating PFES found that compared with no treatment, PFES was 2.31 (95% CI: 1.06-5.02) times more likely to be associated with cure or improvement.19 When compared with PFMT, PFES results in lower subjective cure rates [29% vs 51%, RR: 0.57 (95% CI: 0.37-0.87)], and combining PFMT with PFES did not increase cure or improvement rates over PFMT alone [RR: 1.10 (95% CI: 0.95-1.28)]. Elitone is an FDA-approved surface-applied PFES device designed for at-home use that can be purchased over the Internet without a prescription. Only one small prospective study has evaluated this device in 20 women over a 6-week period, reporting a 75% reduction in incontinence episodes, 85% reduction in pad usage, and an improvement in quality of life.20 More studies are needed to determine the true efficacy of this intervention relative to other treatments. Although most studies do not focus exclusively on females of reproductive age, this population contributes to most study cohorts and as such is expected to yield similar results.
Weighted Vaginal Cones
Vaginal cones are graded weights that are inserted into the vagina and used to help women identify and contract their pelvic floor muscles, which prevents the weights from slipping out. As the pelvic floor musculature gains strength and endurance, women can incrementally increase the weight to effect further progress. The devices are available without a prescription and can be ordered from many online retailers. Although the available literature is inconsistent due to variability in devices and regimens, a Cochrane Database review concluded that limited evidence suggests that weighted vaginal cones offer similar efficacy rates compared with PFMT but provide no added benefit when used in conjunction with PFMT.21 As such, vaginal cones may offer benefit to women who do not have access to or elect not to use formal pelvic floor physical therapy but desire feedback about the efficacy and progress of their PFMT.
Vaginal Inserts and Pessaries
Intravaginal inserts are another mainstay of conservative therapy and include over-the-counter disposable bladder support options such as Impressa and nondisposable, prescription options such as Uresta and the conventional continence pessary. Downsides to all vaginal inserts are that they need to be removed for sexual intercourse and they require some degree of maintenance (insertion and removal).
Impressa is a disposable vaginal insert that mimics a tampon but is shaped to provide suburethral support. Although comparative data are lacking, initial single-arm studies demonstrated that 94% of patients reported significant improvements in leakage episodes (>70% reduction) and quality of life.22 Adverse events were mild and included but were not limited to vaginal discomfort, pain, spotting, and candidiasis. Impressa comes in 3 sizes and includes instructions for determining optimal fit. Its main limitations are cost and the recommendation that it not be worn for more than 12 consecutive hours due to the risk of toxic shock syndrome.
Conventional nondisposable continence pessaries have been available as a treatment option for SUI for decades. Data from the ATLAS RCT demonstrated that continence pessaries were equally as effective as formal pelvic floor physical therapy, resulting in a roughly 40% to 50% reduction in SUI with consistent use.23 It should be noted that continence pessaries must be oriented such that the knob directly supports the urethra, making insertion more difficult for some patients. Uresta is a bell-shaped rubber insert designed for easier vaginal insertion, self-positioning, and removal. In the initial open-label, single-arm phase I and phase II studies, the device was associated with significant reductions in SUI symptoms, improvements in quality of life, urgency UI, and an over 50% reduction in pad weight.24 However, comparative trials are lacking, so its performance relative to more established therapies is not known. In addition, the device is costly (roughly US $300) and is not typically covered by commercial insurance.
ACOG and AUGS suggest that vaginal inserts are good options for patients who are unlikely to adhere to PFMT regimens or desire more immediate relief of their symptoms.6 Vaginal inserts provide a simple and effective interim solution for busy young women until they are able to pursue more definitive therapy. In our practice, we also find that vaginal inserts are a good option for patients who experience SUI with easily identifiable triggers (such as exercise) because their use can be limited to those activities.
Energy-Based Devices
Given that the pathophysiology of SUI is thought to be due in part to weakening of collagen-dependent tissues in the pelvic floor, energy-based devices (EBDs) such as erbium YAG (Er:YAG) laser and fractional CO2 laser have been evaluated for the treatment of SUI because these devices are intended to promote collagen recruitment to tissues. Recently, AUGS released a consensus statement on the use of vaginal EBDs for the treatment of SUI and concluded that there is a significant knowledge gap regarding the safety and efficacy of EBDs for gynecologic indications, including SUI, and that the risks may outweigh any potential benefit.25
Pharmacologic Therapy
Duloxetine (Cymbalta, Eli Lilly, Indianapolis, IN), a dual serotonin and noradrenaline reuptake inhibitor has been approved in the United Kingdom as a pharmacologic treatment for SUI at a recommended dose of 40 mg twice daily.26 A systematic review of 10 placebo-controlled RCTs demonstrated a significantly larger proportion of women with at least 50% reduction in incontinence episode frequency [52% vs 33%; RR: 1.56 (95% CI: 1.46-1.66), P < 0.001] compared with placebo.27 However, duloxetine has failed to receive approval for the treatment of SUI in the United States over concerns for liver toxicity and suicidality. A 2017 meta-analysis of the European data noted that while improvement in SUI-related symptoms was found, the harm from duloxetine may outweigh the benefits, and cautioned against use.28 As such, off-label use of duloxetine may play a limited role in the management of SUI in younger women, particularly those with concomitant depression, but is not currently included in the clinical pathway.
Surgical Intervention
The gold standard and most commonly performed surgical intervention for SUI is the synthetic midurethral sling (MUS). This is typically a 30-minute procedure performed under anesthesia, with short-term efficacy ranging from 62% to 98% and long-term efficacy ranging from 43% to 92%.29 Adverse events are rare, at less than 5%, but include immediate postoperative complications such as bleeding, visceral injury, and urinary retention, as well as delayed complications such as vaginal exposure of mesh, persistent pain, and mesh erosion into surrounding organs. It is important to inform patients that the synthetic MUS differs from vaginal prolapse repair mesh kits, which are no longer on the market due to high complication rates.
There are limited data specifically addressing MUS in women of childbearing age, but several studies have reported outcomes stratified by age. A population-based study evaluating sling insertion and revision rates noted that 10.5% of women undergoing MUS surgery were younger than 40 years.30 Compared with an older population (older than 70 years), women aged 18 to 39 years were nearly 2 times more likely to require sling excision or revision [hazard ratio (HR): 1.91, 95% CI: 1.22-2.99], though it is not entirely clear why. However, absolute rates in both groups were low suggesting that MUS is a safe and effective option for women of all ages, including those of childbearing age.
Nonetheless, the conventional recommendation has been to delay MUS surgery until completion of childbearing as data were lacking with regard to subsequent pregnancy, its impact on efficacy, and risk of complications. Several recent studies have addressed these knowledge gaps, calling into question the recommendation that women must defer definitive treatment of their symptoms. For example, in a population-based cohort reporting 10-year follow-up of women who underwent MUS, those who delivered a child (regardless of route) after MUS placement did not have higher rates of incontinence than women who did not have a delivery after MUS.31 Furthermore, there was no difference in SUI recurrence or reoperation rates between women who delivered vaginally and those who underwent cesarean delivery. Pregnancy complications attributable to sling presence have been reported and are rare, including recurrent UTI, urinary retention necessitating Foley catheter or sling lysis, and pyelonephritis.
Although data are currently limited to case series and cohort studies, it does seem that SUI recurrence and reoperation rates are low in women who become pregnant and give birth after MUS placement. This suggests that with appropriate counseling, MUS is a reasonable option even for young women who may not have completed childbearing. Finally, cesarean delivery should not be recommended on the basis of prior MUS alone, as the presence of a sling does not seem to increase the risk of complications during vaginal delivery.
Finally, although other surgical treatment options exist for the treatment of SUI such as urethral bulking, Burch retropubic urethropexy, pubovaginal sling, and artificial urinary sphincters, the data supporting use of these techniques in women of childbearing age are extremely limited. In addition, each of these techniques has been proven to have either a lower efficacy or a higher complication rate compared with MUS; review of these techniques is beyond the scope of this review.
When to Refer to a Subspecialist
Several aspects of a patient's history or physical examination should prompt referral to an incontinence subspecialist, typically female pelvic medicine and reconstructive surgery (FPMRS). Such triggers include concern for a diagnosis other than straightforward/uncomplicated SUI, concern for an underlying neurologic disorder that could impact bladder function, incomplete bladder emptying (typically a post void residual >100mL), prior failed surgical procedures for SUI, or if the obstetrician/gynecologist has exhausted conservative treatment options and does not, in the routine scope of his or her practice, perform SUI surgery (Figure 1). Although urodynamics are not required for the evaluation of or surgical intervention for SUI, they can be helpful if there is concern for other pathology and generally, the need for urodynamics will prompt subspecialty referral.
Conclusion
SUI is a common and treatable condition, and obstetrician/gynecologists are highly likely to encounter it in patients of all ages including those who may not have completed childbearing. The diagnosis is usually straightforward and can be made with a history, physical examination, and urinalysis. Most conservative interventions are low-risk with minimal adverse events and are safe in women who may be planning future pregnancies. Of all the nonsurgical options, PFMT has the most robust evidence base supporting its safety and efficacy. Women with bothersome SUI who fail conservative interventions or wish to pursue more definitive options can be referred to an FPMRS subspecialist for evaluation and management as data suggest that more invasive options are efficacious and safe in women of all ages, including those planning future pregnancy.
Practice Pearls
* Diagnosis of SUI requires a history; physical examination, including supine cough stress test; urinalysis; and evaluation of PVR volume.
* Weight loss of 5% to 10% of body weight can result in more than 50% improvement in symptoms of SUI.
* PFMT is the most effective conservative therapy available for the treatment of SUI, with approximately 50% cure or improvement rate, and supervised PFMT tends to be favored to at-home Kegel exercises.
* It remains unclear whether the addition of BF, PFES, or vaginal cones adds benefit to PFMT.
* Synthetic MUS is the most effective treatment option for SUI.
* Childbirth (regardless of route) after MUS placement is safe and does not seem to increase the risk of SUI recurrence or sling complications.
* Referral to subspecialists should be made when the diagnosis of SUI is not straightforward, other pathology is suspected, or when patients wish to pursue more definitive interventions and the obstetrician/gynecologist does not have adequate experience with the surgical management of SUI.
REFERENCES