Should women be offered elective cesarean section in the hope of preserving pelvic floor function?

Development of Predictive Risk Models of Postpartum Stress Urinary Incontinence for Primiparous and Multiparous Women

OBJECTIVES

To develop risk predictive models of postpartum stress urinary incontinence (SUI) for both primiparous and multiparous women.

MATERIALS AND METHODS

From July 2016 to July 2017, 815 singleton pregnant women without incontinence before pregnancy who were 18 years or older and admitted to 2 hospitals in Shenzhen, China, were enrolled. Pregnancy-related data were collected at enrollment. Delivery information was obtained from electronic medical records. Telephone follow-up was conducted to investigate SUI at 6 weeks postpartum. Multivariable logistic regression analyses using stepwise selection were used to establish predictive models for postpartum SUI for all women, and separately for primiparous and multiparous. Internal validation of the models was performed with discrimination and calibration using a bootstrapping (1,000 resampling) method.

RESULTS

The analysis included 727 participants. The prevalence of postpartum SUI was 15.96% (116/727), 12.5% (49/393) for primiparous women and 20.1% (67/334) for multiparous women, with a significant difference between them (p = 0.008). For primiparous women, the predictive postpartum SUI model included age, abortion/miscarriage history, SUI during pregnancy, and mode of delivery. For multiparous women, pre-pregnancy BMI, abortion/miscarriage history, SUI during pregnancy, and mode of delivery were included in the model. There was satisfactory calibration between the models' predicted probability of postpartum SUI and the observed probability for both primiparous and multiparous women (Hosmer-Lemeshow test, p = 0.390 for primiparous and 0.364 for multiparous women). The optimism-corrected C-statistic of the models by bootstrapping stepwise was 0.763 (95% confidence interval [CI]: 0.693-0.833) for primiparous women and 0.783 (95% CI: 0.726-0.841) for multiparous women.

CONCLUSION

We developed predictive models of postpartum SUI for both primiparous and multiparous women. This approach may provide a useful tool for high-risk prediction of postpartum SUI before and after delivery.

The impact of cesarean delivery on pelvic floor dysfunction in lysyl oxidase like-1 knockout mice

OBJECTIVE

: Lysyl oxidase like-1 (LOXL1) knockout mice have abnormal elastic fiber homeostasis and frequently develop pelvic floor dysfunction after pregnancy and delivery. The objective of this study was to test the hypothesis that tissue changes associated with vaginal delivery lead to pelvic floor dysfunction as a result of abnormal elastic fiber homeostasis.

METHODS

: Female LOXL1 knockout mice delivered either spontaneously or by cesarean delivery. Mice were assessed weekly for pelvic organ prolapse (POP). At 12 weeks postpartum, lower urinary tract function was assessed by cystometry and leak-point pressure testing. Urethrovaginal cross-sections were analyzed using a histologic grading scale to assess elastin fiber disorganization.

RESULTS

: A total of 39 mice delivered by spontaneous vaginal delivery and 36 by cesarean delivery. Twelve weeks after spontaneous vaginal delivery or cesarean delivery, 23 (59%) and 11 (31%) mice had developed POP, respectively. The mean time to develop POP was 7.2 weeks after spontaneous vaginal delivery and 10.5 weeks after cesarean delivery (log rank, P = 0.0008). The Cox proportional hazard ratio was 0.55 (95% confidence interval, 0.38-0.79). Mice with POP had increased frequency of bladder contractions not associated with voiding during cystometry (P = 0.02). POP, but not mode of delivery, was associated with increased elastic fiber disorganization.

CONCLUSIONS

: Cesarean delivery delays the development of POP in LOXL1 knockout mice. POP is associated with increased bladder contraction frequency and increased elastic fiber disorganization in the urethra and vagina. The mechanisms underlying these findings warrant further investigation.

Can levator avulsion be predicted antenatally?

OBJECTIVE

We sought to determine whether antepartum prediction of major levator trauma is feasible.

STUDY DESIGN

A prospective longitudinal study was undertaken on 488 pregnant nulliparous women seen between 36-38 weeks and again 4 months after delivery. All underwent an interview and 4-dimensional transperineal ultrasound. Diagnosis of levator trauma (avulsion) on tomographic ultrasound was correlated with predelivery demographic variables and ultrasound parameters.

RESULTS

In all, 367 women returned for postpartum assessment after normal vaginal delivery (n = 187), vacuum/forceps (n = 54), and cesarean section (n = 126). Avulsion was diagnosed in 34 vaginally parous women (14%). Maternal age, family history of cesarean section, hiatal dimensions, levator muscle strain, bladder neck descent, and subpubic arch angle were not associated with avulsion. The only predictor identified was a lower body mass index (P = .005).

CONCLUSION

Antepartum prediction of major levator trauma may be difficult or impossible. Future studies should focus on modification of current obstetric practices and antepartum interventions applicable to the general population.

Pelvic organ prolapse

Pelvic organ prolapse is downward descent of female pelvic organs, including the bladder, uterus or post-hysterectomy vaginal cuff, and the small or large bowel, resulting in protrusion of the vagina, uterus, or both. Prolapse development is multifactorial, with vaginal child birth, advancing age, and increasing body-mass index as the most consistent risk factors. Vaginal delivery, hysterectomy, chronic straining, normal ageing, and abnormalities of connective tissue or connective-tissue repair predispose some women to disruption, stretching, or dysfunction of the levator ani complex, connective-tissue attachments of the vagina, or both, resulting in prolapse. Patients generally present with several complaints, including bladder, bowel, and pelvic symptoms; however, with the exception of vaginal bulging, none is specific to prolapse. Women with symptoms suggestive of prolapse should undergo a pelvic examination and medical history check. Radiographic assessment is usually unnecessary. Many women with pelvic organ prolapse are asymptomatic and do not need treatment. When prolapse is symptomatic, options include observation, pessary use, and surgery. Surgical strategies for prolapse can be categorised broadly by reconstructive and obliterative techniques. Reconstructive procedures can be done by either an abdominal or vaginal approach. Although no effective prevention strategy for prolapse has been identified, considerations include weight loss, reduction of heavy lifting, treatment of constipation, modification or reduction of obstetric risk factors, and pelvic-floor physical therapy.

A urogynecologist's view ofthe pelvic floor effects of vaginal delivery/cesarean section for the urologist

Pregnancy and parturition have been implicated in the development of pelvic floor dysfunction. These disorders include urinary incontinence, fecal incontinence, pelvic organ prolapse, and other pelvic and sexual dysfunctions. The urologist caring for women with urinary dysfunction needs to be familiar with the causes of pelvic floor dysfunction and their implications. Defects of the pelvic floor have clearly resulted from the traumatic effect of vaginal delivery. The likely mechanisms of injuries during vaginal delivery involve stretching and compression of the pudendal nerve and peripheral branches, as well as an additional tearing of muscles and connective tissue. Optimal management of labor and optimal techniques of repair of unavoidable sphincteric lacerations, ante- and postpartum pelvic floor muscle conditioning, and timely and proper indications for cesarean delivery will minimize the effect of incidental traumatic delivery.

Parity, mode of delivery, and pelvic floor disorders

OBJECTIVE

This study aimed to assess the associations between parity, mode of delivery, and pelvic floor disorders.

METHODS

The prevalence of pelvic organ prolapse, stress urinary incontinence, overactive bladder, and anal incontinence was assessed in a random sample of women aged 25-84 years by using the validated Epidemiology of Prolapse and Incontinence Questionnaire. Women were categorized as nulliparous, vaginally parous, or only delivered by cesarean. Adjusted odds ratios and 95% confidence intervals (CIs) for each disorder were calculated with logistic regression, controlling for age, body mass index, and parity.

RESULTS

In the 4,458 respondents the prevalence of each disorder was as follows: 7% prolapse, 15% stress urinary incontinence, 13% overactive bladder, 25% anal incontinence, and 37% for any one or more pelvic floor disorders. There were no significant differences in the prevalence of disorders between the cesarean delivery and nulliparous groups. The adjusted odds of each disorder increased with vaginal parity compared with cesarean delivery: prolapse = 1.82 (95% CI 1.04-3.19), stress urinary incontinence = 1.81 (95% CI 1.25-2.61), overactive bladder = 1.53 (95% CI 1.02-2.29), anal incontinence = 1.72 (95% CI 1.27-2.35), and any one or more pelvic floor disorders = 1.85 (95% CI 1.42-2.41). Number-needed-to-treat analysis revealed that 7 women would have to deliver only by cesarean delivery to prevent one woman from having a pelvic floor disorder.

CONCLUSION

The risk of pelvic floor disorders is independently associated with vaginal delivery but not with parity alone. Cesarean delivery has a protective effect, similar to nulliparity, on the development of pelvic floor disorders when compared with vaginal delivery.

LEVEL OF EVIDENCE

II-2.