Has the prevalence of levator avulsion after forceps delivery changed over the last six decades? A retrospective study in a urogynaecological population.

OBJECTIVE: Forceps delivery is associated with a higher risk of maternal birth trauma. It is speculated that it is due to sub-optimal use of forceps in inexperienced hands. The aim of this study was to determine the association between time of forceps birth and prevalence of levator avulsion over the last six decades. STUDY DESIGN: This was a retrospective analysis of datasets of women with a history of forceps delivery, seen at a tertiary urogynaecological centre between January 2014 and August 2018. They had undergone a standardized interview, clinical examination and four-dimensional translabial ultrasound. Archived imaging data was reviewed for levator avulsion offline at a later date, blinded against all clinical data. Associations between levator avulsion, maternal age at first vaginal birth, the weight of the first vaginally born baby, and time since forceps delivery categorised by decade were tested by univariable analysis. Factors found to be significant on univariable analysis were included in a multivariable logistic regression model to test the association between prevalence of levator avulsion and time of forceps delivery while controlling for confounders. RESULTS: In total, 2026 patients were seen during the study period. Among them 511 (25.2%) had a history of forceps delivery. Fourteen volume datasets were incomplete or missing, leaving 497 complete datasets for analysis. Mean age at presentation was 58 ± 12 years (23-91). Mean body mass index was 29 ± 6 kg/m2. Mean age at first delivery was 25 ± 5 years. Mean birth weight of the first vaginal birth was 3454 ± 557 g. 457 women (92%) had had one forceps delivery, 31 had two forceps deliveries (6%) and 9 had three forceps deliveries (2%). Mean time interval between forceps delivery and assessment was 32 ± 13 years (0.3-64.8). 229 women (46%) were diagnosed with levator avulsion. The prevalence of avulsion after forceps increased significantly from 34% to 56% between 1950 and 2017 (P = 0.04). However this difference became insignificant when controlling for maternal age at 1st vaginal delivery and birth weight. CONCLUSIONS: We found no evidence of a changed prevalence of levator avulsion at forceps delivery over the last 67 years.

Is location of urethral kinking a confounder of association between urethral closure pressure and stress urinary incontinence?

OBJECTIVES: Intact urethral support and normal sphincter function are deemed important for urinary continence. We aimed to test whether the location of urethral kinking (as the probable anatomical correlate of maximal pressure transmission) is associated with stress urinary incontinence and/or urodynamic stress incontinence. METHODS: This was a retrospective study of women seen at a tertiary urogynecological center in 2017. Patients had undergone an interview, multichannel urodynamic testing and four-dimensional translabial ultrasound examination. Those with a history of anti-incontinence surgery, absence of urethral kinking on ultrasound and/or missing or inadequate ultrasound volume data were excluded. Volume data were used to assess urethral mobility using a semi-automated Excel® urethral motion profile program. Mobility vectors were calculated using the formula √((x valsalva - x rest )2 + (y valsalva - y rest )2 ), where x and y are the coordinates of six equidistant points along the length of the urethra from the bladder neck to the external urethral meatus. The location of urethral kinking was identified as a concave contour of the urethra on the vaginal side in the midsagittal plane on maximum Valsalva maneuver. The distance between the center of the kink and the bladder neck was measured and expressed as a centile in relation to the total length of the urethra, using the formula: (distance from bladder neck/total length of urethra) × 100. Univariate and multivariate analyses were performed to test the associations of stress urinary incontinence and urodynamic stress incontinence with age, maximum urethral pressure, urethral mobility vectors and location of urethral kinking. RESULTS: Of 450 women seen during the study period, 61 were excluded owing to previous incontinence surgery and 82 owing to absence of urethral kinking, inadequate volume data or missing data, leaving 307 women included, of whom 227 (74%) complained of stress urinary incontinence and 211 (69%) complained of urgency urinary incontinence. 190 (62%) of the women were diagnosed with urodynamic stress incontinence. On multivariate analysis, maximum urethral pressure (36 vs 50 cmH2 O; P < 0.001), mid-urethral mobility (2.27 vs 2.03 cm; P = 0.003) and location of urethral kinking (63.1st vs 59.7th centile; P = 0.002) were associated significantly with urodynamic stress incontinence. The location of urethral kinking was associated with stress urinary incontinence on univariate analysis (P = 0.026) but not on multivariate analysis (P = 0.21). CONCLUSIONS: The location of urethral kinking is associated with urodynamic stress incontinence. The further urethral kinking is from the mid urethra, the more likely is urodynamic stress incontinence. This provides circumstantial evidence for the pressure-transmission theory of stress urinary continence. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Does the Epi-No(®) birth trainer prevent vaginal birth-related pelvic floor trauma? A multicentre prospective randomised controlled trial.

OBJECTIVE: Vaginal childbirth may result in levator ani injury secondary to overdistension during the second stage of labour. Other injuries include perineal and anal sphincter tears. Antepartum use of a birth trainer may prevent such injuries by altering the biomechanical properties of the pelvic floor. This study evaluates the effects of Epi-No(®) use on intrapartum pelvic floor trauma. DESIGN: Multicentre prospective randomised controlled trial. SETTING: Two tertiary obstetric units in Australia. POPULATION: Nulliparous women carrying an uncomplicated singleton term pregnancy. METHODS: Participants were assessed clinically and with 4D translabial ultrasound in the late third trimester, and again at 3-6 months postpartum. Women randomised to the intervention group were asked to use the Epi-No(®) device from 37 weeks of gestation until delivery. MAIN OUTCOME MEASURES: Levator ani, anal sphincter, and perineal trauma diagnosed clinically and/or with translabial ultrasound imaging. RESULTS: Of 660 women randomised, 504 (76.4%) returned for assessment at a mean of 5 months postpartum. There was no significant difference in the incidence of levator avulsion [12 versus 15%; relative risk (RR) 0.82, 95% confidence interval (95% CI) 0.51-1.32; absolute risk reduction (ARR) 0.03, 95% CI -0.04 to 0.09; P = 0.39], irreversible hiatal overdistension (13 versus 15%; RR 0.86, 95% CI 0.52-1.42; ARR 0.02, 95% CI -0.05 to 0.09; P = 0.51), clinical anal sphincter trauma (7 versus 6%; RR 1.12, 95% CI 0.49-2.60; ARR -0.01, 95% CI -0.05 to 0.06; P = 0.77), and perineal tears (51 versus 53%; RR 0.96, 95% CI 0.78-1.17; ARR 0.02, 95% CI -0.08 to 0.13; P = 0.65). A marginally higher rate of significant defects of the external anal sphincter on ultrasound was observed in the intervention group (21 versus 14%; RR 1.44, 95% CI 0.97-2.20; ARR -0.06, 95% CI -0.13 to 0.05; P = 0.07). CONCLUSION: Antenatal use of the Epi-No(®) device is unlikely to be clinically beneficial in the prevention of intrapartum levator ani damage, or anal sphincter and perineal trauma. TWEETABLE ABSTRACT: No evidence of a protective effect of the Epi-No(®) device on intrapartum pelvic floor rauma.