New Measures for Predicting Birth-Related Pelvic Floor Trauma

Pelvic floor injury during vaginal birth is life-altering and preventable: what can we do about it?

Pelvic floor disorders after childbirth have distressing lifelong consequences for women, requiring more than 300,000 women to have surgery annually. This represents approximately 10% of the 3 million women who give birth vaginally each year. Vaginal birth is the largest modifiable risk factor for prolapse, the pelvic floor disorder most strongly associated with birth, and is an important contributor to stress incontinence. These disorders require 10 times as many operations as anal sphincter injuries. Imaging shows that injuries of the levator ani muscle, perineal body, and membrane occur in up to 19% of primiparous women. During birth, the levator muscle and birth canal tissues must stretch to more than 3 times their original length; it is this overstretching that is responsible for the muscle tear visible on imaging rather than compression or neuropathy. The injury is present in 55% of women with prolapse later in life, with an odds ratio of 7.3, compared with women with normal support. In addition, levator damage can affect other aspects of hiatal closure, such as the perineal body and membrane. These injuries are associated with an enlarged urogenital hiatus, now known as antedate prolapse, and with prolapse surgery failure. Risk factors for levator injury are multifactorial and include forceps delivery, occiput posterior birth, older maternal age, long second stage of labor, and birthweight of >4000 g. Delivery with a vacuum device is associated with reduced levator damage. Other steps that might logically reduce injuries include manual rotation from occiput posterior to occiput anterior, slow gradual delivery, perineal massage or compresses, and early induction of labor, but these require study to document protection. In addition, teaching women to avoid pushing against a contracted levator muscle would likely decrease injury risk by decreasing tension on the vulnerable muscle origin. Providing care for women who have experienced difficult deliveries can be enhanced with early recognition, physical therapy, and attention to recovery. It is only right that women be made aware of these risks during pregnancy. Educating women on the long-term pelvic floor sequelae of childbirth should be performed antenatally so that they can be empowered to make informed decisions about management decisions during labor.

An International Continence Society (ICS)/ International Urogynecological Association (IUGA) joint report on the terminology for the assessment and management of obstetric pelvic floor disorders

AIMS

The terminology of obstetric pelvic floor disorders should be defined and reported as part of a wider clinically oriented consensus.

METHODS

This Report combines the input of members of two International Organizations, the International Continence Society (ICS) and the International Urogynecological Association (IUGA). The process was supported by external referees. Appropriate clinical categories and a sub-classification were developed to give coding to definitions. An extensive process of 12 main rounds of internal and 2 rounds of external review was involved to exhaustively examine each definition, with decision-making by consensus.

RESULTS

A terminology report for obstetric pelvic floor disorders, encompassing 357 separate definitions, has been developed. It is clinically-based with the most common diagnoses defined. Clarity and user-friendliness have been key aims to make it usable by different specialty groups and disciplines involved in the study and management of pregnancy, childbirth and female pelvic floor disorders. Clinical assessment, investigations, diagnosis, conservative and surgical treatments are major components. Illustrations have been included to supplement and clarify the text. Emerging concepts, in use in the literature and offering further research potential but requiring further validation, have been included as an Appendix. As with similar reports, interval (5-10 year) review is anticipated to maintain relevance of the document and ensure it remains as widely applicable as possible.

CONCLUSION

A consensus-based Terminology Report for obstetric pelvic floor disorders has been produced to support clinical practice and research.

Effect of prolonged second stage of labor on pelvic floor function: A prospective cohort study

INTRODUCTION AND HYPOTHESIS

To evaluate the effect of the second stage of labor (SSL) lasting > 2 h on pelvic floor function.

METHODS

This single-center prospective cohort study included primiparous women with SSL > 2 h treated at Tongji Hospital between January 2018 and December 2019 (case group). A matched group of women with similar newborn weight and SSL < 2 h were recruited simultaneously (control group). Stress urinary incontinence (SUI) and pelvic floor muscle (PFM) characteristics were measured at 6 weeks, 6 months, and finally 1 year postpartum.

RESULTS

A total of 63 pairs of primiparous women completed 1-year follow-up. The incidence of SUI in the case group was significantly higher than that in the control group at 6 weeks postpartum (P = 0.020); however, the differences were not significant at 1 year postpartum (P=1.00). PFM endurance was significantly lower in the case group at 6 weeks (P = 0.000), 6 months (P = 0.000), and 1 year (P = 0.011) after childbirth. There was no difference in PFM strength between the two groups. The maximal voluntary contraction (MVC) of PFM was significantly lower in the case group at 6 weeks postpartum (P = 0.007), but the differences were not significant at 1 year postpartum (P = 0.197). PFM endurance and MVC were higher at 1 year than at 6 weeks postpartum in both groups.

CONCLUSIONS

The SSL > 2 h increased the incidence of SUI at 6 weeks postpartum and decreased PFM endurance for 1 year.

Severe Perineal Trauma in a Brazilian Southeastern Tertiary Hospital: A Retrospective Cohort Study

OBJECTIVE

This study aimed to investigate the prevalence of severe perineal trauma (obstetric and anal sphincter injury [OASIS]) in a tertiary high-risk pregnancy facility and the associated factors.

METHODS

A retrospective electronic chart review on perineal lacerations was performed from the period of April 2017 to February 2019. Obstetric and anal sphincter injury was diagnosed by a rectal examination. Primary outcome was the prevalence of OASIS (third- and fourth-degree perineal tear). Independent variables were maternal, intrapartum, and neonatal characteristics. Univariate and multivariate analyses with logistic regression models were performed. A P value lower than 0.05 was considered significant.

RESULTS

The prevalence of OASIS (third/fourth-degree laceration) was 1.51% (43/2846) in our population. Our population was mostly white (66.3%) and mostly primiparous (52.1%). By comparison, the prevalence of first/second-degree laceration was 43% (1223/2846). Selective episiotomy occurred in 18.73% (517/2761) of patients, and it was not associated with OASIS (P = 0.211). Advanced maternal age (P = 0.196), higher number of vaginal examinations (P = 0.169), fetal presentation (P = 0.533), and duration of second stage (P = 0.757) were not associated with OASIS. Univariate analysis has found that forceps delivery (odds ratio [OR], 3.68 [1.74-7.79]; P = 0.001), neonatal macrossomy (OR, 3.42 [1.02-11.43]; P = 0.045), and larger head circumference (OR, 1.15 [1.02-1.32]; P = 0.026) were risk factors for OASIS, whereas higher gravidity reduced the risk (OR, 0.61 [0.42-0.91] for OASIS. However, after multivariate analysis, only head circumference (OR, 1.86 [1.10-3.14]; P = 0.020) remained as a risk factor.

CONCLUSIONS

Larger neonatal head circumference increased in 86% the risk for severe perineal trauma in this cohort of women.

Is there a correlation between pelvic floor dysfunction symptoms during pregnancy and the duration of the second stage of labor?

BACKGROUND

Pelvic floor dysfunction (PFD) most commonly results from weakened or injured muscles and ligaments whose purpose is to support the pelvic floor. Many studies have placed vaginal delivery and prolonged second stage of labor (SSL) as major risk factors for PFD, supposedly through generating enhanced pressure in the pelvic area. Although many studies describe the effects of vaginal delivery and labor on structure and function of the pelvic floor, not much is known regarding PFD deriving from pregnancy and its prevalence and severity in the postpartum. We aimed to evaluate whether a correlation exists between PFD symptoms during pregnancy and the duration of the SSL.

METHODS

We conducted a cross sectional study of 200 women who gave birth at Soroka University Medical Center, Beer-Sheva, Israel. Those who had consented completed the Pelvic Floor Distress Inventory-20 (PFDI-20), a condition specific questionnaire developed to measure quality-of-life and the extent of injury to the pelvic floor in women with all forms of PFD. The duration of the SSL and clinical and obstetrical characteristics were retrieved from the participants' medical records. We assessed correlations using Spearman's correlation coefficient.

RESULTS

PFD during pregnancy was found to be correlated to the duration of the SSL (R = -0.183, p = .021). When evaluating each component of the PFDI-20 separately, CRAD was significantly correlated with the duration of the SSL (R = -0.195, p = .014).

CONCLUSIONS

There is a correlation between PFD symptoms during pregnancy, specifically symptoms of CRAD and the duration of the SSL.

Pelvic floor ultrasound finds after episiotomy and severe perineal tear: systematic review and meta-analysis

AIM

Vaginal delivery is a well-known risk factor for pelvic floor muscle (PFM) injuries, mainly when associated to prolonged labor, instrumental birth and perineal trauma such as episiotomy and perineal tears. The purpose of this meta-analysis was to test the hypothesis that episiotomy and severe perineal tear may increase the risk of pelvic floor damage.

METHODS

We performed a systematic literature search through electronic databases including MEDLINE via PubMed, LILACS via BVS, Embase via Elsevier and Cochrane Library up to January 2019. We included articles that reported as outcome one or more morphological aspects of the PFM evaluated by ultrasonography in primiparous women three to 24 months postpartum. This review is registered in the PROSPERO database (registration number: CRD42017075750).

RESULTS

the final selection was composed of 18 articles for the systematic review, and 10 for the meta-analysis. Women with levator ani muscle (LAM) avulsion were 1.77 times more likely to have undergone episiotomy (OR = 1.77, CI 95% 1.25-2.51, five trials), 4.31 times more likely to have severe perineal tear (OR = 4.31, CI 95% 2.34-7.91, two trials). Women with defects in the anal sphincters were 2.82 times more likely to have suffered severe perineal tear (OR = 2.82, 95% CI 1.71-4.67, three trials).

CONCLUSIONS

Both episiotomy and severe perineal tear are risk factors for LAM avulsion and anal sphincter injury, and this can be useful for identifying women who are at greater risk of developing PFM dysfunctions.

How do sustained birth tears after vaginal birth affect birth tear patterns in a subsequent birth?

Background Tears are common after vaginal birth, and different impact factors are known. However, the impact of tears from a previous birth to the tears of a subsequent birth is unknown. Therefore, we aimed to evaluate the distribution of birth tear patterns according to the sustained tears in a previous birth, in addition to other impact factors. Methods In a retrospective cohort study, we evaluated all women up to parity 4 with subsequent vaginal, singleton births of vertex presentation at ≥37 + 0 gestational weeks between 1/2005 and 12/2016. Their tears were grouped into tear patterns and were analyzed by parity. Tear patterns in the subsequent births were analyzed in association to the patterns of the previous births and impact factors were evaluated. Results We counted 4017 births in 1855 women [P1: 1368 (34.1%), P2: 1730 (43.1%), P3: 741 (18.4%), P4: 178 (4.4%)]. The frequency of tears and episiotomies decreased with higher parity, whereas the frequency of intact perineum increased. Twenty-eight different unique tear patterns were found. We could show that birth tear patterns changed with increasing parity and were associated with sustained tears in a previous birth. In addition, some impact factors on tear patterns could be identified. Conclusion The distribution of the single tear types is in accordance with the current literature. However, it is new that distinct tear patterns are associated to sustained tear patterns of previous births. Furthermore, we demonstrated some weak associations of tear patterns to certain impact factors, such as more episiotomies, low-grade perineal or vaginal tears isolated or in combination with other tears with increasing fetal weight and head circumference in the higher parities, and with a longer duration of the second stage and the pushing phase in lower parities.

Pelvic floor disorders in postpartum adolescents in the Western Amazon: a cross-sectional study

PURPOSE

To analyze the postpartum pelvic floor disorders (PFD) and mode of delivery among adolescents, late adolescents, and young women from Western Amazon.

PATIENTS AND METHODS

Cross-sectional study was carried out in the urban area of Western Amazon in the city of Rio Branco, Acre, Brazil, from October 2016 to February 2017. This is a convenience sample of women up to 30 years who completed six months postpartum, separated in three groups according to maternal age: adolescents (age ≤19 years), late adolescents (20-24 years), and young women (25-30 years). Participants were home interviewed and answered Pelvic Floor Distress Inventory-20 (PFDI-20). Delivery clinical data were collected from patient's medical records.

RESULTS

In total, 285 participants were interviewed: 41 adolescents, 103 late adolescents, and 141 young women. After controlling for confounding factors, prevalences of PFD were higher in the adolescents' group compared with the young women's group (urinary incontinence [UI], prevalence ratio [PR] = 1.75, 95% CI 1.14-2.69; urge urinary incontinence [UUI], PR = 1.88, 95% CI 1.02-3.47; stress urinary incontinence, PR = 2.00, 95% CI 1.11-3.62; fecal incontinence [FI], PR = 4.40, 95% CI 1.36-14.27). PFDI-20 scores also presented higher values in the adolescent group (Pelvic Organ Prolapse Distress Inventory [POPDI], PR = 2.02, 95% CI 1.49-2.75; urinary distress inventory [UDI], PR = 2.09, 95% CI 1.47-2.98; PFDI, PR = 2.12, 95% CI 1.47-2.98). Analyzing the influence of cesarean section, adolescents have higher prevalence of UI (PR = 1.84, 95% CI 1.04-3.26, P=0.037), UUI (PR = 2.36, 95% CI 1.03-5.40, P=0.042), and FI (PR = 4.09, 95% CI 1.21-13.81, P=0.023). In addition, POPDI (PR = 2.15, 95% CI 1.60-2.89, P<0.001), UDI (PR = 2.25, 95% CI 1.61-3.16, P<0.001), and PFDI (PR = 2.27, 95% CI 1.68-3.08, P<0.001) scores are also higher among adolescents where the baby is born by cesarean section.

CONCLUSION

Adolescents present higher prevalence and symptoms of PFD; furthermore, cesarean delivery has a greater negative influence on the pelvic floor of adolescents when compared with young women. This reinforces the importance of PFD investigation among the adolescent population, mainly in developing countries which have high rates of adolescent pregnancy and cesarean section.

Can we predict levator ani muscle avulsion in instrumental deliveries through intrapartum transperineal ultrasound?

Introduction: To determine whether intrapartum translabial ultrasound (ITU) is useful for the prediction of levator ani muscle (LAM) avulsions in instrumental deliveries (vacuum and forceps). Materials and methods: Prospective, observational study, including (1/2016 - 5/2016) 77 nulliparous women, with singleton pregnancies of ≥37 weeks of gestation and with cephalic presentation, who required vacuum or forceps instrumentation to complete the delivery. The ITU parameters evaluated were Angle of Progression (AoP), Progression Distance (PD), Head Direction (HD), and Midline Angle (MLA), both at rest and with maternal push. Evaluation of LAM avulsion was performed at 6 months postpartum with 3-4D transperineal ultrasound. Complete avulsion was defined as an abnormal insertion of LAM in the lower pubic branch identified in all three central slices. Results: Data from 48 nulliparous women were finally included in the study (34 vacuum and 14 forceps). We observed no difference in obstetric parameters between the two study groups (group with avulsion of LAM -14 cases, 29.2% - and group without avulsion of LAM -34 cases, 70.8%). The "LAM avulsion group" had an AoP and a PD of 136.7 ± 22.4 and 43.5 ± 15.6, respectively, versus 141.6 ± 21.3 and 47.2 ± 16.8 recorded in the group without avulsion (NS), respectively. We obtained a ROC curve for AoP and PD with a push of 0.66 (95% CI, 0.28-1.00) and 0.57 (95% CI, 0.39-0.75), respectively. Conclusions: ITU is not a useful technique to predict the occurrence of LAM avulsion in instrumental deliveries with vacuum or forceps.

A constitutive model description of the in vivo material properties of lower birth canal tissue during the first stage of labor

Remarkable changes must occur in the pelvic floor muscles and tissues comprising the birth canal to allow vaginal delivery. Despite these preparatory adaptations, approximately 13% of women who deliver vaginally for the first time (nulliparas) sustain tears near the origin of the pubovisceral muscle (PVM) which can result in pelvic organ prolapse later in life. To investigate why these tears occur, it is necessary to quantify the viscoelastic behavior of the term pregnant human birth canal. The goal of this study was to quantify the in vivo material properties of the human birth canal, in situ, during the first stage of labor and compare them to published animal data. The results show that pregnant human, ovine and squirrel monkey birth canal tissue can be characterized by the same set of constitutive relations; the interspecies differences were primarily explained by the long time constant, τ₂, with its values of 555s, 1110s, and 2777s, respectively. Quantification of these viscoelastic properties should allow for improved accuracy of computer models aimed at understanding birth-related injuries.