Antenatal and intrapartum consent: Implications of the NSW Consent Manual 2020.

The provision of informed consent for antenatal and intrapartum care remains a contentious issue among healthcare professionals and has been the topic of controversies in the pages of this journal. Recently, the New South Wales (NSW) Department of Health has fundamentally changed the ground rules for the provision of maternity care within the state. In this opinion piece, we try to provide guidance to clinicians to help them deal with the medicolegal environment created by this document which is likely to affect practitioners not just in NSW.

Is vaginal flatus related to pelvic floor functional anatomy?

INTRODUCTION AND HYPOTHESIS: Vaginal flatus is an embarrassing condition that can impair women's quality of life. The underlying pathophysiology is unclear. We aimed to evaluate the association between vaginal flatus and pelvic floor anatomy. METHODS: Retrospective observational study on women seen in a tertiary urogynaecological service. All had undergone a standardised interview, clinical examination and four-dimensional transperineal ultrasound. Offline analysis of volume data was performed blinded against clinical data. RESULTS: Datasets of 570 women were analysed. Five hundred twelve (90%) were vaginally parous. Vaginal flatus was reported by 190 (33%). Mean bother score was 4.2 (SD 3.4, range 0-10). One hundred eighty-five reported frequency of vaginal flatus: it occurred < once a month in 25 (14%), once a month in 70 (38%), once a week in 47 (25%), once daily in 28 (15%) and > once daily in 15 (8%). One hundred two women identified the following precipitating factors: intercourse in 72 (71%), postural change in 22 (22%) and physical activities in 9 (9%). Vaginal birth, central and posterior compartment prolapse, anal incontinence, higher levator resting tone and younger age were associated with vaginal flatus. The latter was moderately correlated with symptom bother (correlation coefficient - 0.21). CONCLUSIONS: Vaginal flatus is a prevalent and bothersome condition affecting one-third of our study population. The condition is associated with pelvic floor functional anatomy. A higher resting tone may confer a higher resistance against which trapped air is expelled during physical activities. Younger age was moderately correlated with symptom bother.

The effect of replacing vacuum with forceps in operative vaginal delivery: an observational study.

INTRODUCTION AND HYPOTHESIS: An increase in vaginal delivery with forceps may increase rates of pelvic floor trauma. This study was designed to predict trauma rates resulting from policies preferencing forceps. METHODS: This is an observational cohort study utilizing data from 660 primiparae enrolled in an RCT in two tertiary obstetric units in Sydney, Australia. Participants were assessed clinically and with 4D translabial ultrasound in the late third trimester and again at 3-6 months postpartum. Incidence of trauma associated with mode of delivery was adjusted to reflect change associated with a conversion of vacuum to forceps delivery. Primary outcome measures were third-/fourth-degree tear, levator avulsion (LA) and external anal sphincter (EAS) trauma diagnosed sonographically. RESULTS: Five hundred four women were seen at a mean of 5.1 (2.3-24.3) months postpartum. After exclusion of 21 because of missing data, 483 women were analysed: 112 (23%) had a CS, 268 (55%) a normal vaginal delivery (NVD), 69 (14%) a vacuum (VD) and 34 (7%) a forceps (FD). One hundred fifty-two women had EAS trauma and/or LA; 17 sustained both. After VD, 32/69 (46%) women suffered LA and/or EAS trauma; after FD, it was 33/34 (97%). Converting VD to FD was estimated to result in an increase in trauma from 152/483 (31%) to 187/483 (39%). A formula can be generated based on local obstetric and ultrasound data to estimate trauma incidence. CONCLUSIONS: A change in obstetric practice resulting in the conversion of primary VD to primary FD would be expected to substantially increase the likelihood of pelvic floor trauma.

Predictors of successful ring pessary use in women with pelvic organ prolapse.

BACKGROUND: Pelvic organ prolapse (POP) is a common chronic health issue. Pessary rings are used for conservative management. To date, there is little evidence on objective anatomical findings as predictors of successful ring pessary management. AIM: To determine any association between history, clinical and four-dimensional translabial ultrasound (TLUS)/pelvic floor ultrasound examination and pessary success. MATERIALS AND METHODS: From November 2013 to November 1015, all new patients presenting with symptomatic prolapse to a tertiary urogynaecological unit underwent an assessment including interview, clinical examination, that is, International Continence Society POPQ (pelvic organ prolapse quantification) and TLUS. Women with symptomatic prolapse were offered conservative management with a ring pessary. Those who agreed had a ring inserted that day. Successful trial of pessary use was defined as continued use for at least three months. Retrospective analysis of imaging data was performed blinded to other data. Statistical analysis was performed to assess the relationship between history, examination and imaging and pessary success. RESULTS: Of 525 patients seen during the inclusion period, 177 had symptomatic prolapse. One hundred and twenty-eight were offered a pessary, 89 accepted. Five had incomplete data, leaving 84. Forty- Two (50%) were still using the pessary at a three-month follow-up. Predictors associated with failure included being pre-menopausal (P = 0.031), a previous hysterectomy (P = 0.051), increasing genital hiatus and perineal body (Gh + Pb) (P = 0.013), posterior compartment prolapse (P = 0.027) and a larger hiatal area on Valsalva on TLUS (P = 0.049). Pre-menopausal status (P = 0.003), increasing Gh + Pb (P = 0.011) and previous hysterectomy (P = 0.001) remained significant on multivariate analysis. CONCLUSIONS: A history of previous hysterectomy is a predictor of pessary failure as are Gh+Pb on Valsalva and premenopausal status.

Contributing factors in forceps associated pelvic floor trauma.

INTRODUCTION AND HYPOTHESIS: Levator avulsion occurs in 10-35% of women after a first vaginal delivery, with forceps being the main risk factor. Three mechanisms have been proposed to account for the high risk of trauma: the additional space requirement, increased speed of distension, and/ or greater force. This study examines the additional space requirements associated with forceps to determine any associated increase in avulsion risk. METHODS: This was an in vitro simulation study of spatial requirements for delivery of a fetal head by forceps, with mathematical modelling of spatial requirements using data from a local observational study. A balloon device was used to model head circumferences through the range of expected measurements at term, with measurements taken after application of three different types of forceps. Each measurement was performed in triplicate. RESULTS: On average, forceps increased the circumference of the fetal head by 1.01 cm for Wrigley's, 1.04 cm for Kielland's, and 1.64 cm for Neville-Barnes forceps, resulting in an estimated increase in the diameter of the fetal head by 0.32 cm, 0.33 cm, and 0.52 cm, respectively. This increase was linear throughout the tested range. In 534 singleton pregnancies at term, we determined an odds ratio (OR) of 1.11 per centimeter head circumference for avulsion. Hence, the additional space requirement due to forceps explains ORs of 1.11, 1.12, and 1.19 for avulsion, depending on forceps type. CONCLUSIONS: The effect of forceps on avulsion risk is not fully explained by the increase in space requirement alone. Other factors, such as shortened time to maximum distension and/or increased peak force applied may contribute to the excess risk.

The impact of variations in obstetric practice on maternal birth trauma.

INTRODUCTION AND HYPOTHESIS: Forceps delivery and length of second stage are risk factors of maternal birth trauma, i.e., levator ani muscle (LAM) avulsion and anal sphincter trauma. The cesarean section (CS) rate has recently become the key performance indicator because of its increase worldwide. Attempts to reduce CS rates seem to have led to an increase in forceps deliveries and longer second stages. This study aimed to determine the association between variations in obstetric practice (between hospitals) and maternal birth trauma. METHODS: This was a retrospective ancillary analysis involving 660 nulliparous women carrying an uncomplicated singleton term pregnancy in a prospective perinatal intervention trial at two Australian tertiary obstetric units. They had been seen antenatally and at 3-6 months postpartum for a standardized clinical assessment between 2007 and 2014. Primary outcome measures were sonographically diagnosed LAM and external anal sphincter (EAS) trauma. RESULTS: The incidence of LAM avulsion (11.5% vs. 21.3%, P = 0.01) and composite trauma, i.e., LAM avulsion ± EAS injury (29.2% vs. 39.7%, P = 0.03) were higher in one of the two hospitals, where the forceps delivery rate was also higher (10.9% vs. 2.6%, P < 0.001). BMI (OR 0.9, P = 0.02), length of second stage (OR 1.01, P = 0.02) and forceps delivery (OR 5.24, P < 0.001) were significant predictors of the difference in LAM avulsion incidence between the hospitals. Maternal age (OR 1.06, P < 0.04) and forceps delivery (OR 8.66, P < 0.001) were significant predictors for composite trauma. CONCLUSIONS: A higher incidence of LAM avulsion and composite trauma in one of the two hospitals was largely explained by a higher forceps delivery rate.

Atraumatic normal vaginal delivery: how many women get what they want?

BACKGROUND: Trauma to the perineum, levator ani complex, and anal sphincter is common during vaginal childbirth, but often clinically underdiagnosed, and many women are unaware of the potential for long-term damage. OBJECTIVE: In this study we use transperineal ultrasound to identify how many women will achieve a normal vaginal delivery without substantial damage to the levator ani or anal sphincter muscles, and to create a model to predict patient characteristics associated with successful atraumatic normal vaginal delivery. STUDY DESIGN: This is a retrospective, secondary analysis of data sets gathered in the context of an interventional perinatal imaging study. A total of 660 primiparas, carrying an uncomplicated singleton pregnancy, underwent an antepartum and postpartum interview, vaginal exam (Pelvic Organ Prolapse Quantification), and 4-dimensional translabial ultrasound. Ultrasound data were analyzed for levator trauma and/or overdistention and residual sphincter defects. Postprocessing analysis of ultrasound volumes was performed blinded against clinical data and analyzed against obstetric data retrieved from the local maternity database. Levator avulsion was diagnosed if the muscle insertion at the inferior pubic ramus at the plane of minimal hiatal dimensions and within 5 mm above this plane on tomographic ultrasound imaging was abnormal, ie the muscle was disconnected from the inferior pubic ramus. Hiatal overdistensibility (microtrauma) was diagnosed if there was a peripartum increase in hiatal area on Valsalva by >20% with the resultant area ≥25 cm2. A sphincter defect was diagnosed if a gap of >30 degrees was seen in ≥4 of 6 tomographic ultrasound imaging slices bracketing the external anal sphincter. Two models were tested: a first model that defines severe pelvic floor trauma as either obstetric anal sphincter injury or levator avulsion, and a second, more conservative model, that also included microtrauma. RESULTS: A total of 504/660 women (76%) returned for postpartum follow-up as described previously. In all, 21 patients were excluded due to inadequate data or intercurrent pregnancy, leaving 483 women for analysis. Model 1 defined nontraumatic vaginal delivery as excluding operative delivery, obstetric anal sphincter injuries, and sonographic evidence of levator avulsion or residual sphincter defect. Model 2 also excluded microtrauma. Of 483 women, 112 (23%) had a cesarean delivery, 103 (21%) had an operative vaginal delivery, and 17 (4%) had a third-/fourth-degree tear, leaving 251 women who could be said to have had a normal vaginal delivery. On ultrasound, in model 1, 27 women (6%) had an avulsion and 31 (6%) had a residual defect, leaving 193/483 (40%) who met the criteria for atraumatic normal vaginal delivery. In model 2, an additional 33 women (7%) had microtrauma, leaving only 160/483 (33%) women who met the criteria for atraumatic normal vaginal delivery. On multivariate analysis, younger age and earlier gestation at time of delivery remained highly significant as predictors of atraumatic normal vaginal delivery in both models, with increased hiatal area on Valsalva also significant in model 2 (all P ≤ .035). CONCLUSION: The prevalence of significant pelvic floor trauma after vaginal child birth is much higher than generally assumed. Rates of obstetric anal sphincter injury are often underestimated and levator avulsion is not included as a consequence of vaginal birth in most obstetric text books. In this study less than half (33-40%) of primiparous women achieved an atraumatic normal vaginal delivery.

Can pelvic floor trauma be predicted antenatally?

INTRODUCTION: Levator trauma is a risk factor for the development of pelvic organ prolapse. We aimed to identify antenatal predictors for significant damage to the levator ani muscle during a first vaginal delivery. MATERIAL AND METHODS: A retrospective observational study utilizing data from two studies with identical inclusion criteria and assessment protocols between 2005 and 2014. A total of 1148 primiparae with an uncomplicated singleton pregnancy were recruited and assessed with translabial ultrasound at 36 weeks antepartum and 871 (76%) returned for reassessment 3-6 months postpartum. The ultrasound data of vaginally parous women were analyzed for levator avulsion and microtrauma. The former was diagnosed if the muscle insertion at the inferior pubic ramus in the plane of minimal hiatal dimensions and within 5 mm above were abnormal on tomographic ultrasound imaging. Microtrauma was diagnosed in women with an intact levator and if there was a postpartum increase in hiatal area on Valsalva by >20% with the resultant area ≥25 cm2 . RESULTS: The complete datasets of 844 women were analyzed. Among them, 609 delivered vaginally: by normal vaginal delivery in 452 (54%), a vacuum birth in 102 (12%) and a forceps delivery in 55 (6%). Levator avulsion was diagnosed in 98 and microtrauma in 97. On multivariate analysis, increasing maternal age, lower body mass index and lower bladder neck descent were associated with avulsion. Increased bladder neck descent and a family history of cesarean section (CS) were associcated with microtrauma. CONCLUSIONS: Maternal age, body mass index, bladder neck descent and family history of CS are antenatal predictors for levator trauma.

Intrapartum predictors of maternal levator ani injury.

INTRODUCTION: Damage to the pelvic floor during vaginal childbirth is common, and may take the form of levator avulsion or irreversible overdistension of the levator hiatus (microtrauma). Such trauma is a major risk factor for pelvic organ prolapse later in life. In this study we aimed to identify intrapartum risk factors for levator trauma. MATERIAL AND METHODS: This is a retrospective analysis of data obtained in two perinatal studies on primiparous women. Between 2005 and 2014, 1148 women carrying an uncomplicated singleton pregnancy in the late third trimester were seen for 4D pelvic floor ultrasound and an interview. They were invited for a repeat assessment at three months postpartum. RESULTS: Of 1148 women, 871 (76%) returned for assessment at a mean of five months postpartum. The datasets of 844 women were analyzed due to missing data or concurrent pregnancy in 27. In all, 452 (54%) had a normal vaginal delivery, 102 (12%) a vacuum, 55 (6%) a forceps, and 235 (28%) a cesarean section. On multivariate analysis forceps, length of second stage and obstetric anal sphincter tears were significantly associated with levator avulsion. There were no significant predictors identified for irreversible overdistension. CONCLUSIONS: The use of forceps, a prolonged second stage, and obstetric anal sphincter tears were associated with levator avulsion. There were no associated intrapartum predictors for hiatal overdistension.

The Association Between Levator-Urethra Gap Measurements and Symptoms and Signs of Female Pelvic Organ Prolapse.

OBJECTIVES: Levator avulsion is associated with pelvic organ prolapse in women. It is diagnosed clinically by a widened gap on palpation between the insertion of the puborectalis muscle on the inferior pubic ramus and the urethra. This gap can also be assessed on imaging. This study aimed to determine the association between sonographically determined levator-urethral gap (LUG) measurements and symptoms and signs of prolapse. METHODS: This is a retrospective study on 450 women seen in a tertiary urogynecological center for symptoms of pelvic floor dysfunction between January 2013 and February 2014. All had a standardized interview, International Continence Society Pelvic Organ Prolapse Quantification assessment and 4-dimensional translabial ultrasound. Post-imaging analysis of archived ultrasound volumes for LUG measurement was undertaken on tomographic slices at the plane of minimal hiatal dimensions and within 5-mm cranial to this plane, bilaterally at an interslice interval of 2.5 mm, blinded against all clinical data. A LUG of 25 mm or greater was considered abnormal. RESULTS: Mean LUG and maximum LUG in individuals were 22.5 mm (SD, 4.6) and 26.4 mm (SD, 6.0), respectively, with at least 1 abnormal LUG in 51% (n = 222). An abnormal LUG in all 3 slices involving the plane of minimal hiatal dimensions and within 5 mm cranial to this plane on at least 1 side was fulfilled in 24% (n = 103). The LUG measurements were strongly associated with bother, symptoms and signs of prolapse (P < 0.001 to 0.002). This remained significant on multivariate analysis controlling for potential confounding factors. CONCLUSIONS: Sonographically determined LUG is strongly associated with symptoms, symptom bother, and pelvic organ prolapse on clinical examination and imaging.

The association between maternal age at first delivery and risk of obstetric trauma.

BACKGROUND: There are a number of poor birth outcomes with advancing maternal age. Although there is some evidence of a higher risk of trauma to obstetric anal sphincter and the levator ani muscle with advancing age, findings to date are inconclusive. OBJECTIVE: The aim of this study was to assess the risk of pelvic floor injury using translabial 3- and 4-dimensional ultrasound relative to advancing maternal age in primiparous women after a singleton vaginal delivery at term and to determine any association between maternal age and obstetric trauma, including obstetric anal sphincter injuries, levator avulsion, and irreversible overdistension of the levator hiatus. STUDY DESIGN: This is a subanalysis of a perinatal intervention trial conducted in a specialist urogynecology referral unit at 2 tertiary units. All primiparous women with singleton birth at term underwent 3- and 4-dimensional translabial pelvic floor ultrasound both ante- and postnatally for the assessment of the obstetric trauma including levator ani muscle avulsion, hiatal overdistension to 25 cm(2) or more, and obstetric anal sphincter injuries. A multivariate logistic regression analysis was performed to examine the association between maternal age and obstetric trauma diagnosed on 3- and 4-dimensional translabial ultrasound. Multiple confounders were included, and the most significant (forceps and vacuum delivery) were used for probability modeling. RESULTS: Of 660 women recruited for the original study, a total of 375 women who had a vaginal delivery with complete data sets were analyzed. A total of 174 women (46.4%) showed evidence of at least 1 form of major pelvic floor trauma. Advancing maternal age at first delivery carries with it a significant incremental risk of major pelvic floor trauma with an odds ratio of 1.064 for overall risk of injury for each increasing year of age past age 18 years (P = .003). The probability of any type of trauma appears to be substantially higher for forceps delivery. Vacuum delivery appears to increase the risk of obstetric anal sphincter injuries but not of levator avulsion. CONCLUSION: There is a significant association between the risk of major pelvic floor injury and increasing maternal age at first delivery.