Predictive factors for obstetric anal sphincter injury in primiparous women: systematic review and meta-analysis.

OBJECTIVES: The primary objective was to perform a systematic review of predictive factors for obstetric anal sphincter injury (OASI) occurrence at first vaginal delivery, with the diagnosis made by ultrasound (US-OASI). The secondary objective was to report on incidence rates of sonographic anal sphincter (AS) trauma, including trauma that was not clinically reported at childbirth, among the studies providing data for our primary objective. METHODS: We conducted a systematic search of MEDLINE, EMBASE, Web of Science, CINAHL, The Cochrane Library and ClinicalTrials.gov databases. Both observational cohort studies and interventional trials were eligible for inclusion. Study eligibility was assessed independently by two authors. Random-effects meta-analyses were performed to pool effect estimates from studies reporting on similar predictive factors. Summary odds ratio (OR) or mean difference (MD) is reported with 95% CI. Heterogeneity was assessed using the I2 statistic. Methodological quality was assessed using the Quality in Prognosis Studies tool. RESULTS: A total of 2805 records were screened and 21 met the inclusion criteria (16 prospective cohort studies, three retrospective cohort studies and two interventional non-randomized trials). Increasing gestational age at delivery (MD, 0.34 (95% CI, 0.04-0.64) weeks), shorter antepartum perineal body length (MD, -0.60 (95% CI, -1.09 to -0.11) cm), labor augmentation (OR, 1.81 (95% CI, 1.21-2.71)), instrumental delivery (OR, 2.13 (95% CI, 1.13-4.01)), in particular forceps extraction (OR, 3.56 (95% CI, 1.31-9.67)), shoulder dystocia (OR, 12.07 (95% CI, 1.06-137.60)), episiotomy use (OR, 1.85 (95% CI, 1.11-3.06)) and shorter episiotomy length (MD, -0.40 (95% CI, -0.75 to -0.05) cm) were associated with US-OASI. When pooling incidence rates, 26% (95% CI, 20-32%) of women who had a first vaginal delivery had US-OASI (20 studies; I2 = 88%). In studies reporting on both clinical and US-OASI rates, 20% (95% CI, 14-28%) of women had AS trauma on ultrasound that was not reported clinically at childbirth (16 studies; I2 = 90%). No differences were found in maternal age, body mass index, weight, subpubic arch angle, induction of labor, epidural analgesia, episiotomy angle, duration of first/second/active-second stages of labor, vacuum extraction, neonatal birth weight or head circumference between cases with and those without US-OASI. Antenatal perineal massage and use of an intrapartum pelvic floor muscle dilator did not affect the odds of US-OASI. Most (81%) studies were judged to be at high risk of bias in at least one domain and only four (19%) studies had an overall low risk of bias. CONCLUSION: Given the ultrasound evidence of structural damage to the AS in 26% of women following a first vaginal delivery, clinicians should have a low threshold of suspicion for the condition. This systematic review identified several predictive factors for this. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Novel artificial intelligence approach for automatic differentiation of fetal occiput anterior and non-occiput anterior positions during labor.

OBJECTIVES: To describe a newly developed machine-learning (ML) algorithm for the automatic recognition of fetal head position using transperineal ultrasound (TPU) during the second stage of labor and to describe its performance in differentiating between occiput anterior (OA) and non-OA positions. METHODS: This was a prospective cohort study including singleton term (> 37 weeks of gestation) pregnancies in the second stage of labor, with a non-anomalous fetus in cephalic presentation. Transabdominal ultrasound was performed to determine whether the fetal head position was OA or non-OA. For each case, one sonographic image of the fetal head was then acquired in an axial plane using TPU and saved for later offline analysis. Using the transabdominal sonographic diagnosis as the gold standard, a ML algorithm based on a pattern-recognition feed-forward neural network was trained on the TPU images to discriminate between OA and non-OA positions. In the training phase, the model tuned its parameters to approximate the training data (i.e. the training dataset) such that it would identify correctly the fetal head position, by exploiting geometric, morphological and intensity-based features of the images. In the testing phase, the algorithm was blinded to the occiput position as determined by transabdominal ultrasound. Using the test dataset, the ability of the ML algorithm to differentiate OA from non-OA fetal positions was assessed in terms of diagnostic accuracy. The F1 -score and precision-recall area under the curve (PR-AUC) were calculated to assess the algorithm's performance. Cohen's kappa (κ) was calculated to evaluate the agreement between the algorithm and the gold standard. RESULTS: Over a period of 24 months (February 2018 to January 2020), at 15 maternity hospitals affiliated to the International Study group on Labor ANd Delivery Sonography (ISLANDS), we enrolled into the study 1219 women in the second stage of labor. On the basis of transabdominal ultrasound, they were classified as OA (n = 801 (65.7%)) or non-OA (n = 418 (34.3%)). From the entire cohort (OA and non-OA), approximately 70% (n = 824) of the patients were assigned randomly to the training dataset and the rest (n = 395) were used as the test dataset. The ML-based algorithm correctly classified the fetal occiput position in 90.4% (357/395) of the test dataset, including 224/246 with OA (91.1%) and 133/149 with non-OA (89.3%) fetal head position. Evaluation of the algorithm's performance gave an F1 -score of 88.7% and a PR-AUC of 85.4%. The algorithm showed a balanced performance in the recognition of both OA and non-OA positions. The robustness of the algorithm was confirmed by high agreement with the gold standard (κ = 0.81; P < 0.0001). CONCLUSIONS: This newly developed ML-based algorithm for the automatic assessment of fetal head position using TPU can differentiate accurately, in most cases, between OA and non-OA positions in the second stage of labor. This algorithm has the potential to support not only obstetricians but also midwives and accoucheurs in the clinical use of TPU to determine fetal occiput position in the labor ward. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Under-classified obstetric anal sphincter injuries.

INTRODUCTION AND HYPOSTHESIS: Obstetric anal sphincter injuries (OASIs) that are missed at delivery can have long-term consequences. OASIs that are under-classified at delivery are likely to be inadequately repaired, resulting in a persistent anal sphincter defect. We aimed to identify women who have persistent defects on endoanal ultrasound, inconsistent with the original diagnosis, and compare the effect on St Mark's incontinence scores (SMIS). We also aimed to look for changes in numbers of under-classification over time. METHODS: Records of women attending a perineal clinic who had endoanal ultrasound from 2012 to 2020 were reviewed. Women who had a modified Starck score implying a defect greater than the classification [indicated by the depth of external anal sphincter or internal anal sphincter (IAS) defect] at delivery were identified. RESULTS: A total of 1056 women with a diagnosis of 3a or 3b tears were included. Of these, 120 (11.36%) were found to have a defect greater than the original diagnosis and therefore were incorrectly classified at delivery. Women who had a 3b tear diagnosed at delivery, but had an IAS defect, had a significantly higher SMIS (p < 0.01). When comparing two 4-year periods, there was a significant improvement in the diagnosis of IAS tears. CONCLUSION: Some women with OASIs that have under-classified OASIs are associated with worse anorectal symptoms. This is likely because of an incomplete repair. Some improvement in diagnosis of IAS tears has been noted. We propose improved training in OASIs can help reduce the number of incorrectly classified tears and improve repair.

Can transperineal ultrasound improve the diagnosis of obstetric anal sphincter injuries?

INTRODUCTION AND HYPOTHESIS: Women with missed obstetric anal sphincter injuries (OASIs) are at an increased risk of anal incontinence. Our aim was to assess the accuracy of three-dimensional (3D) transperineal ultrasound (TPUS) compared with clinical examination for detecting OASIs. METHODS: A cross-sectional study of women undergoing their first vaginal delivery. Perineal trauma was initially assessed by the doctor or midwife performing the delivery (accoucheur) and women were then re-examined by the trained research fellow (KW). A 3D TPUS was performed immediately after delivery before suturing to identify OASIs. The research fellow's clinical diagnosis was used as the reference standard. A power calculation determined that 216 women would be required for the study. RESULTS: Two hundred and sixty-four women participated and 226 (86%) delivered vaginally. Twenty-one (9%) sustained OASIs. Six (29%) of these tears were missed by the accoucheur but were identified by the research fellow. TPUS identified 19 of the 21 (90.5%) OASIs. One percent (n = 2) had sonographic appearances of an anal sphincter defect that was not seen clinically. The positive and negative predictive value of TPUS to detect OASIs was 91% and 99% respectively. TPUS identified 91% of OASIs compared with 71% detected by the accoucheur, which was not statistically significant. CONCLUSIONS: The detection rate of OASIs with TPUS and with the clinical findings of the accoucheur was similar. Given the training and financial implications needed for TPUS, attention needs to be focused on the training of midwives and doctors to identify anal sphincter injuries by clinical examination.

Obstetric anal sphincter injuries (OASIS): using transperineal ultrasound (TPUS) for detecting, visualizing and monitoring the healing process.

PURPOSE: The aim of this study was to examine whether OASIS, and its extent, can be confirmed or excluded using transperineal ultrasound (TPUS). A further objective of this study was to monitor the healing process over a period of 6 months and to establish a connection between the sonographic appearance of obstetric anal sphincter injury (OASIS) and anal incontinence. MATERIALS AND METHODS: In this retrospective clinical study, women with OASIS who gave birth between March 2014 and August 2019 were enrolled. All the patients underwent TPUS 3 days and 6 months after delivery. A GE E8 Voluson ultrasound system with a 3.5-5 MHz ultrasound probe was used. The ultrasound images showed a third-degree injury, with the measurement of the width of the tear and its extent (superficial, partial, complete, EAS and IAS involvement). A positive contraction effect, a sign of sufficient contraction, was documented. Six months after delivery, a sonographic assessment of the healing (healed, scar or still fully present) was performed. A Wexner score was obtained from each patient. The patients' medical histories, including age, parity, episiotomy and child's weight, were added. RESULTS: Thirty-one of the 55 recruited patients were included in the statistical evaluation. Three patients were excluded from the statistical evaluation because OASIS was excluded on TPUS 3 days after delivery. One patient underwent revision surgery for anal incontinence and an inadequately repaired anal sphincter injury, as shown sonographic assessment, 9 days after delivery. Twenty patients were excluded for other reasons. The results suggest that a tear that appears smaller (in mm) after 3 days implies better healing after 6 months. This effect was statistically significant, with a significance level of alpha = 5% (p = 0.0328). Regarding anal incontinence, women who received an episiotomy had fewer anal incontinence symptoms after 6 months. The effect of episiotomy was statistically significant, with a significance level of alpha = 5% (p = 0.0367). CONCLUSION: TPUS is an accessible, non-invasive method for detecting, quantifying, following-up and monitoring OASIS in patients with third-degree perineal tears. The width, as obtained by sonography, is important with regard to the healing of OASIS. A mediolateral episiotomy seems to prevent anal incontinence after 6 months.

Predicting cesarean delivery for failure to progress as an outcome of labor induction in term singleton pregnancy.

BACKGROUND: Induction of labor is one of the most common interventions in modern obstetrics, and its frequency is expected to continue to increase. There is inconsistency as to how failed induction of labor is defined; however, the majority of studies define success as the achievement of vaginal delivery. Induction of labor in nulliparous women poses an additional challenge with a 15% to 20% incidence of failure, ending in emergency operative deliveries. The Bishop score has been traditionally used before decisions for induction of labor. Nonetheless, it is subjective and prone to marked interobserver variation. Several studies have been conducted to find alternative predictors, yet a reliable, objective method still remains to be introduced and validated. Hence, there is still a need for the development of new predictive tools to facilitate informed decision making, optimization of resources, and minimization of potential risks of failure. Furthermore, a peripartum transperineal ultrasound scan has been proven to provide objective, noninvasive assessment of labor. OBJECTIVE: This study aimed to assess the feasibility of developing and validating an objective and reproducible model for the prediction of cesarean delivery for failure to progress as an outcome of labor induction in term singleton pregnancies. STUDY DESIGN: This was a prospective observational cohort study conducted in Cairo University Hospitals and University of Bologna Hospitals between November 2018 and November 2019. We recruited 382 primigravidae with singleton term pregnancies in cephalic presentation. All patients had baseline Bishop scoring together with various transabdominal and transperineal ultrasound assessments of the fetus, maternal cervix, and pelvic floor. The managing obstetricians were blinded to the ultrasound scan findings. The method and indication of induction of labor, the total duration of stages of labor, mode of birth, and neonatal outcomes were all recorded. Women who had operative delivery for fetal distress or indications other than failure to progress in labor were excluded from the final analysis, leaving a total of 344 participants who were randomly divided into 243 and 101 pregnancies that constituted the model development and cross-validation groups, respectively. RESULTS: It was possible to perform transabdominal and transperineal scans and assess all the required parameters on all study participants. Univariate and multivariate analyses were used for selection of potential predictors and model fitting. The independent predictive variables for cesarean delivery included maternal age (odds ratio, 1.12; P=.003), cervical length (odds ratio, 1.08; P=.04), angle of progression at rest (odds ratio, 0.9; P=.001), and occiput posterior position (odds ratio, 5.7; P=.006). We tested the performance of the prediction model on our cross-validation group. The calculated areas under the curve for the ability of the model to predict cesarean delivery were 0.7969 (95% confidence interval, 0.71-0.87) and 0.88 (95% confidence interval, 0.79-0.97) for the developed and validated models, respectively. CONCLUSION: Maternal age and sonographic fetal occiput position, angle of progression at rest, and cervical length before labor induction are very good predictors of induction outcome in nulliparous women at term.

Umbilical cord prolapse: revisiting its definition and management.

Umbilical cord prolapse is an unpredictable obstetrical emergency with an incidence ranging from 1 to 6 per 1000 pregnancies. It is associated with high perinatal mortality, ranging from 23% to 27% in low-income countries to 6% to 10% in high-income countries. In this review, we specifically addressed 3 issues. First, its definition is not consistent in the current literature, and "occult cord prolapse" is a misnomer because the cord is still above the cervix. We proposed that cord prolapse, cord presentation, and compound cord presentation should be classified according to the positional relationship among the cord, the fetal presenting part, and the cervix. All of them may occur with either ruptured or intact membranes. The fetal risk is highest in cord prolapse, followed by cord presentation, and lastly by compound cord presentation, which replaces the misnomer "occult cord prolapse." Second, the mainstay of treatment of cord prolapse is urgent delivery, which means cesarean delivery in most cases, unless vaginal delivery is imminent. The urgency depends on the fetal heart rate pattern, which can be bradycardia, recurrent decelerations, or normal. It is most urgent in cases with bradycardia, because a recent study showed that cord arterial pH declines significantly with the bradycardia-to-delivery interval at a rate of 0.009 per minute (95% confident interval, 0.0003-0.0180), and this may indicate an irreversible pathology such as vasospasm or persistent cord compression. However, cord arterial pH does not correlate with either deceleration-to-delivery interval or decision-to-delivery interval, indicating that intermittent cord compression causing decelerations is reversible and less risk. Third, while cesarean delivery is being arranged, different maneuvers should be adopted to relieve cord compression by elevating the fetal presenting part and to prevent further cord prolapse beyond the vagina. A recent study showed that the knee-chest position provides the greatest elevation effect, followed by filling of the maternal urinary bladder with 500 mL of fluid, and then the Trendelenburg position (15°) and other maneuvers. However, each maneuver has its own advantages and limitations; thus, they should be applied wisely and with great caution, depending on the actual clinical situation. Therefore, we have proposed an algorithm to guide this acute management.

Caesarean section in the second delivery to prevent anal incontinence after asymptomatic obstetric anal sphincter injury: the EPIC multicentre randomised trial.

OBJECTIVE: To determine whether planned caesarean section (CS) for a second delivery protects against anal incontinence in women with obstetric anal sphincter lesions. DESIGN: Randomised trial. SETTING: Six maternity units in the Paris area. SAMPLE: Women at high risk of sphincter lesions (first delivery with third-degree laceration and/or forceps) but no symptomatic anal incontinence. METHODS: Endoanal ultrasound was performed in the third trimester of the second pregnancy. Women with sphincter lesions were randomised to planned CS or vaginal delivery (VD). MAIN OUTCOME MEASURES: Anal incontinence at 6 months postpartum. Secondary outcomes were urinary incontinence, sexual morbidity, maternal and neonatal morbidities and worsening of external sphincter lesions. RESULTS: Anal sphincter lesions were detected by ultrasound in 264/434 women enrolled (60.8%); 112 were randomised to planned VD and 110 to planned CS. At 6-8 weeks after delivery, there was no significant difference in anal continence between the two groups. At 6 months after delivery, median Vaizey scores of anal incontinence were 1 (interquartile range 0-4) in the CS group and 1 (interquartile range 0-3) in the VD group (P = 0.34). There were no significant differences for urinary continence, sexual functions or for other maternal and neonatal morbidities. CONCLUSIONS: In women with asymptomatic obstetric anal sphincter lesions diagnosed by ultrasound, planning a CS had no significant impact on anal continence 6 months after the second delivery. These results do not support advising systematic CS for this indication. TWEETABLE ABSTRACT: Caesarean section for the second delivery did not protect against anal incontinence in women with asymptomatic obstetric anal sphincter lesions.

Vaginal birth after Cesarean section and levator ani avulsion: a case-control study.

OBJECTIVE: The aim of this study was to explore the risk of levator ani muscle (LAM) avulsion and enlargement of the levator hiatus following vaginal birth after Cesarean section (VBAC) in comparison with vaginal delivery in primiparous women. METHODS: In this two-center observational case-control study, we identified all women who had a term VBAC for their second delivery at the Departments of Obstetrics and Gynecology at the Faculty of Medicine in Pilsen and the 1st Faculty of Medicine in Prague, Charles University, Czech Republic, between 2012 and 2016. Women with a repeat VBAC, preterm birth or stillbirth were excluded from the study. As a control group, we enrolled a cohort of primiparous women who delivered vaginally during the study period. To increase our control sample, we also invited all primiparous women who delivered vaginally in both participating units between May and June 2019 to participate. All participants were invited for a four-dimensional pelvic floor ultrasound scan to assess LAM trauma. LAM avulsion and the area of the levator hiatus were assessed offline from the stored pelvic floor volumes obtained at rest, during maximum contraction and during Valsalva maneuver. The laterality of the avulsion was also noted. The cohorts were then compared using the χ2 test and Wilcoxon's two-sample test according to the normality of the distribution. P < 0.05 was considered statistically significant. Multivariate regression analysis, controlling for age and body mass index (BMI), was also performed. RESULTS: A total of 356 women had a VBAC for their second delivery during the study period. Of these, 152 (42.7%) attended the ultrasound examination and full data were available for statistical analysis for 141 women. The control group comprised 113 primiparous women. A significant difference was observed between the VBAC group and the control group in age (32.7 vs 30.1 years; P < 0.05), BMI (28.4 vs 27.4 kg/m2 ; P < 0.05) and duration of the first and second stages of labor (293.1 vs 345.9 min; P < 0.05 and 27.6 vs 35.3 min; P < 0.05, respectively) at the time of the index birth. The LAM avulsion rate was significantly higher in the VBAC compared with the control group (32.6% vs 18.6%; P = 0.01). The difference between the groups was observed predominantly in the rate of unilateral avulsion and remained significant after controlling for age and BMI (adjusted odds ratio 2.061 (95% CI, 1.103-3.852)). There was no statistically significant difference in the area of the levator hiatus at rest (12.0 vs 12.6 cm2 ; P = 0.28) or on maximum Valsalva maneuver (18.6 vs 18.7 cm2 ; P = 0.55) between the VBAC and control groups. The incidence of levator hiatal ballooning was comparable between the groups (17.7% and 18.6%; P = 0.86). CONCLUSIONS: VBAC is associated with a significantly higher rate of LAM avulsion than is vaginal birth in nulliparous women. The difference was significant even after controlling for age and BMI. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Change in cervical length after arrested preterm labor and risk of preterm birth.

OBJECTIVE: To assess the association between preterm birth and cervical length after arrested preterm labor in high-risk pregnant women. METHODS: In this post-hoc analysis of a randomized clinical trial, transvaginal cervical length was measured in women whose contractions had ceased 48 h after admission for threatened preterm labor. At admission, women were defined as having a high risk of preterm birth based on a cervical length of < 15 mm or a cervical length of 15-30 mm with a positive fetal fibronectin test. Logistic regression analysis was used to investigate the association of cervical length measured at least 48 h after admission and of the change in cervical length between admission and at least 48 h later, with preterm birth before 34 weeks' gestation and delivery within 7 days after admission. RESULTS: A total of 164 women were included in the analysis. Women whose cervical length increased between admission for threatened preterm labor and 48 h later (32%; n = 53) were found to have a lower risk of preterm birth before 34 weeks compared with women whose cervical length did not change (adjusted odds ratio (aOR), 0.24 (95% CI, 0.09-0.69)). The risk in women with a decrease in cervical length between the two timepoints was not different from that in women with no change in cervical length (aOR, 1.45 (95% CI, 0.62-3.41)). Moreover, greater absolute cervical length after 48 h was associated with a lower risk of preterm birth before 34 weeks (aOR, 0.90 (95% CI, 0.84-0.96)) and delivery within 7 days after admission (aOR, 0.91 (95% CI, 0.82-1.02)). Sensitivity analysis in women randomized to receive no intervention showed comparable results. CONCLUSION: Our study suggests that the risk of preterm birth before 34 weeks is lower in women whose cervical length increases between admission for threatened preterm labor and at least 48 h later when contractions had ceased compared with women in whom cervical length does not change or decreases. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Can ultrasound 10 days after obstetric anal sphincter injury predict anal incontinence at long-term follow-up?

INTRODUCTION AND HYPOTHESIS: The objective was to investigate whether endoanal ultrasound (EAUS) performed 10 days after a primary repaired obstetric anal sphincter injury (OASIS) can predict the severity of anal incontinence (AI) in the long term. METHODS: This prospective cohort study included women with a primary repaired 3b-degree tear, 3c-degree tear or fourth-degree tear at Aarhus University Hospital, Denmark, from 1 September 2010 to 31 May 2011. Clinical assessment and EAUS were performed on day 2, day 10, and day 20 after delivery. Functional outcomes were assessed using a questionnaire at the time of all clinical visits and at the long-term follow-up, 7 years after delivery. AI was graded according to the Wexner score and EAUS defects were graded according to the Starck score. RESULTS: Ninety-six out of 99 women consented to participate. Five women had a secondary sphincter repair and were subsequently excluded from follow-up. Fifty-seven women underwent both EAUS 10 days after delivery and answered the long-term follow-up questionnaire. Median follow-up time was 7.7 years (IQR 7.4-7.8). Mean Wexner score was 4.4 ± 4.8 10 days after delivery and 2.5 ± 2.8 at follow-up; thus, the Wexner score improved over time (p = 0.01). Ultrasound sphincter defects were found in 82.6% of the women. Mean Starck score was 3.0 ± 1.8. The risk of AI was 0% (95% CI 0.0-30.8) if the Starck score was 0. No correlation was found between the Starck score and the Wexner score at follow-up. CONCLUSIONS: We found that performing EAUS in the puerperium following OASIS has limited value in predicting long-term AI.

Residual Defects of the Anal Sphincter Complex Following Primary Repair of Obstetrical Anal Sphincter Injuries at a Large Canadian Obstetrical Centre.

OBJECTIVES: To determine the rates of residual anal sphincter defect following primary repair of obstetrical anal sphincter injury (OASIS), and to assess symptomatology in these patients. METHODS: A retrospective observational study of patients who underwent primary repair of an OASIS sustained at Mount Sinai Hospital from January 2016 to June 2017. Records were reviewed for demographic and obstetrical data, symptoms of anal incontinence (AI), and the results of endoanal ultrasonography (EA-US). RESULTS: One hundred and one women sustained an OASIS during the study period, of whom 53 had EA-US performed at Mount Sinai Hospital; 4 women were excluded from this analysis. There were 42 third-degree tears and 7 fourth-degree tears. EA-US revealed residual defects in 22 patients with third-degree tears and 5 patients with fourth-degree tears (52% vs. 71%; P = 0.44).  Twelve patients with third-degree tears and 4 patients with fourth-degree tears reported AI (29% vs. 57%; P = 0.20). EA-US revealed no evidence of a tear in 14 patients clinically diagnosed with third-degree tears and 1 patient clinically diagnosed with a fourth-degree tear (33% vs. 14%). CONCLUSION: These data demonstrate deficiencies in diagnosis and repair of OASIS. Continued training for health care providers on identification and effective repair of OASIS may improve outcomes for women who experience this complication.

The association between sonographic fetal head circumference, obstetric anal sphincter injury and mode of delivery: A retrospective cohort study.

BACKGROUND: There is no consensus to the implications of an increased sonographic fetal head circumference (HC) and its impact on delivery. AIM: To examine if there is any association between sonographic fetal HC, obstetric anal sphincter injury (OASIS) and mode of delivery. MATERIALS AND METHODS: A retrospective cohort study of term, singleton births between April 2017 and March 2019 at a large regional hospital in Australia with a third trimester ultrasound. Logistic regressions were performed investigating sonographic fetal HC and additional risk factors for OASIS. Further multinomial logistic regressions assessed the relationship between the sonographic HC and mode of delivery. Odds ratios and their 95% CIs were reported. RESULTS: Of 667 eligible women, 487 (73%) had vaginal births, with 32 (6.6%) sustaining an OASIS and 180 (27%) had caesarean sections (CS). The sonographic fetal HC did not show an association with OASIS (odds ratio 1.005; CI 0.99-1.01, P = 0.447). A statistically significant association (P < 0.05) with OASIS was found with Asian ethnicity (4.38; 1.5-11.32), prolonged second stage (≥2 h) (4.26; 1.57-10.49) and occiput posterior position (4.01; 1.08-11.92). For women with a sonographic fetal HC ≥ 90th percentile, the odds of having CS compared to a spontaneous vaginal birth are 2.77 (95% CI: 1.36, 5.62; P = 0.005) times higher than those who have a HC < 90th percentile. CONCLUSION: This study does not support the use of sonographic fetal HC in assessing a woman's risk of sustaining an OASIS. Sonographic fetal HC is associated with mode of delivery.

Association of pubovisceral muscle tear with functional capacity of urethral closure: evaluating maternal recovery from labor and delivery.

BACKGROUND: Vaginal birth is a risk factor for pubovisceral muscle tear, decreased urethral closure pressure, and urinary incontinence. The relationship between these 3 factors is complicated. Urinary continence relies on maintaining urethral closure pressure, particularly when low urethral closure pressure can usefully be augmented by a volitional pelvic muscle (Kegel) contraction just before and during stress events like a cough. However, it is unknown whether a torn pubovisceral muscle decreases the ability to increase urethral closure during an attempted pelvic muscle contraction. OBJECTIVE: We tested the null hypothesis that a pubovisceral muscle tear does not affect the ability to increase urethral closure pressure during a volitional pelvic muscle contraction in the Evaluating Maternal Recovery from Labor and Delivery (EMRLD) study. STUDY DESIGN: We studied 56 women 8 months after their first vaginal birth. All had at least 1 risk factor for pubovisceral muscle tear (eg, forceps and long second stage). A tear was assessed bilaterally by magnetic resonance imaging. Urethral closure pressure was measured both at rest and during an attempted volitional pelvic muscle contraction. A Student t test was used to compare urethral closure pressures. Multiple linear regression was used to estimate the effect of a magnetic resonance imaging-confirmed pubovisceral muscle tear on volitionally contracted urethral closure pressure after adjusting for resting urethral closure pressure. RESULTS: The mean age was just a little more than 30 years, with the majority being white. By magnetic resonance imaging measure, unadjusted for other factors, the 21 women with tear had significantly lower urethral closure pressure during an attempted contraction compared with the 35 women without tear (65.9 vs 86.8 cm H2O, respectively, P = .004), leading us to reject the null hypothesis. No significant group difference was found in resting urethral closure pressure. After adjusting for resting urethral closure pressure, pubovisceral muscle tear was associated with lower urethral closure pressure (beta = -21.1, P = .001). CONCLUSION: In the first postpartum year, the presence of a pubovisceral muscle tear did not influence resting urethral closure. However, women with a pubovisceral muscle tear achieved a 25% lower urethral closure pressure during an attempted pelvic muscle contraction than those without a pubovisceral muscle tear. These women with pubovisceral muscle tear may not respond to classic behavioral interventions, such as squeeze when you sneeze or strengthen through repetitive pelvic muscle exercises. When a rapid rise to maximum urethral pressure is used as a conscious volitional maneuver, it appears to be reliant on the ability to recruit the intact pubovisceral muscle to simultaneously contract the urethral striated muscle.

Are there differences in the damage to the pelvic floor between malmstrom's and kiwi omnicup vacuums? A multicenter study.

OBJECTIVES: The objective of this study is to investigate a multicenter study to establish if differences exist in the levator ani muscle avulsion (LAM) rates between deliveries performed with Malmstrom's vacuum and the Kiwi vacuum. STUDY DESIGN: A prospective, multicenter observational study with 199 primiparous subjects was performed. All patients had undergone vaginal delivery by vacuum (Malmstrom's or Kiwi). Avulsion was defined as an abnormal insertion of LAM in the lower pubic branch in the multiplanar mode, as identified in the three central sections by transperineal 3/4D echography 6 months after delivery. The area of ​​the levator hiatus was measured in the plane of minimum dimensions at rest, during the Valsalva maneuver and during contraction. RESULTS: LAM avulsion occurred in 33.1% of cases in which Malmstrom's vacuum was used and in 29.4% of cases in which the Kiwi vacuum was used (the difference was not statistically significant), which resulted in a crude odds ratio (OR) of 0.977 (0.426, 2.241; P = .957) and an adjusted OR of 2.90 (0.691; 12.20; P = .146). Women in the Malmstrom's vacuum group had a larger LHA at rest 14.77 vs 12.64 cm2 ; P = .001) and at maximum contraction (13.41 vs 10.83 cm2 ; P < 0.001) in comparison with the Kiwi group, although the difference did not reach statistical significance under Valsalva maneuver (18.71 vs 17.21 cm2 ; P = .051).Differences between both groups were detected in the measurements of the hiatus area levator at rest (14.77 vs 12.64 cm2 ), during the Valsalva maneuver (18.71 vs 17.21 cm2 ) and during maximum contraction (13.41 vs 10.83 cm2 ). CONCLUSIONS: In the present study, Malmstrom's vacuum was not associated with a higher risk of LAM in comparison with Kiwi's Omnicup.

The role of a new three-dimensional ultrasound technique in the diagnosis of levator ani muscle avulsion.

AIMS: To evaluate the intermethod agreement between the tomographic ultrasound imaging (TUI), considered as the gold standard, and the OmniView-VCI in the diagnosis of levator ani muscle (LAM) avulsion and in the measurement of levator-urethral gap (LUG). METHODS: We acquired dynamic 4D transperineal ultrasound volumes from 114 women. Each data set was analyzed on maximal pelvic floor contraction by TUI and OmniView-VCI techniques to check for LAM avulsion. Moreover, we measured LUG using both TUI and OmniView-VCI, twice by an operator and once by another to assess intraobserver and interobserver reproducibility. Reproducibility and intermethod agreement were studied by means of intraclass correlation coefficient (ICC) and Cohen's kappa coefficient. RESULTS: In the diagnosis of ani levator avulsion, the two techniques showed a good agreement (Cohen's κ = 0.691, 95% confidence interval [CI], 0.522-0.860; P < .001); we also reported a good intraobserver and interobserver agreement (Cohen's κ = 0.738, 95% CI, 0.597-0.879; P < .001, and Cohen's κ = 0.864, 95% CI, 0.750-0.978; P < .001, respectively). LUG measurements by OmniView-VCI technique showed high intraobserver (ICC 0.895; 95% CI, 0.866-0.918) and interobserver (ICC 0.821; 95% CI, 0.774-0.858) reproducibility. High intermethod agreement was demonstrated between the two methods (ICC 0.813; 95% CI, 0.764-0.853). The area under the receiver-operating characteristic curve of LUG in predicting avulsion was 0.931 (0.868-0.994, 95% CI; P < .001) with 24 mm showing the best sensitivity (82%) and specificity (97%). CONCLUSIONS: OmniView-VCI is a reliable method for LUG measurement and for levator avulsion diagnosis.

Malmström vacuum or Kielland forceps: which causes more damage to pelvic floor?

OBJECTIVE: To determine whether differences exist in the rate of levator ani muscle (LAM) avulsion between women who had undergone either Malmström vacuum delivery (MVD) or Kielland forceps delivery (KFD), allowing for potential confounding factors. METHODS: This was a prospective observational study of nulliparous women undergoing instrumental delivery using Malmström vacuum extractor or Kielland forceps, at two hospital centers in Spain. Fetal head position (anterior, posterior or transverse) and fetal head station (low or mid) were assessed by ultrasound and digital examination, respectively. Avulsion was defined on tomographic ultrasound imaging as an abnormal insertion of the LAM in the three central slices from the plane of minimal hiatal dimensions. RESULTS: In total, 414 patients were included in the study (212 MVD and 202 KFD). We observed a higher rate of LAM avulsion in the KFD group (KFD 49.5% vs MVD 32.5%; P = 0.001). When the results were evaluated according to fetal head position and station, we observed no differences in LAM avulsion. The crude odds ratio (OR) for the difference in avulsion between women in the KFD and MVD groups was 2.03 (95% CI, 1.36-3.03). However, when adjusted for duration of second stage of labor, fetal head circumference and fetal head station, the OR was no longer statistically significant (OR, 2.14 (95% CI, 0.95-4.85); P = 0.068). CONCLUSION: When potential confounding factors are taken into account, the rate of LAM avulsion does not differ between women according to whether they have undergone KFD or MVD. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

The consequences of undiagnosed obstetric anal sphincter injuries (OASIS) following vaginal delivery.

INTRODUCTION AND HYPOTHESIS: We aimed to compare anal and urinary incontinence symptoms and anal manometry between women with undiagnosed obstetric anal sphincter injuries (OASIS) and women who had OASIS diagnosed and repaired. METHODS: This was a matched retrospective cohort study. Each missed OASI was matched with a diagnosed OASI for severity [minor (3a/b) or major (3c)], parity and length of follow-up. Women completed the modified St Mark's Incontinence Score and International Consultation on Incontinence Questionnaire. Women with OASIS or those without OASIS but with anal incontinence symptoms were seen in perineal clinic for perineal examinations, anorectal manometry and three-dimensional endoanal ultrasound 8-12 weeks postnatally or in a subsequent pregnancy. RESULTS: Forty missed OASIS were matched with 40 recognised OASIS (16 3a/b; 24 3c). The median modified St Mark's scores were higher for missed tears [11 (4, 15) vs. 1 (0, 4), p < 0.001] as well as the urinary incontinence scores [4 (0, 6) vs. 0 (0, 2), p = 0.01] than for the control group. Missed OASIS patients had a shorter perineal body [1.6 ± 1.3 vs. 2.4 ± 0.8, p = 0.009]. All missed OASIS had larger defects on endoanal ultrasound. One in four missed OASIS required further surgery [aOR 4.1 (95% CI 1.0-16.3), p = 0.04] and almost all needed colorectal input [aOR 24.1 (95% CI 7.3-80.0), p < 0.0001]. There were no differences in anal manometry. CONCLUSIONS: Women with symptomatic missed OASIS are compromised in terms of anal and urinary incontinence symptoms, sphincter defect size and perineal body size requiring additional colorectal input. This highlights the importance of preventing OASIS and perseverance with training to diagnose OASIS.

Association between sexual dysfunction and avulsion of the levator ani muscle after instrumental vaginal delivery.

INTRODUCTION: The effects of levator ani muscle (LAM) avulsion after instrumental delivery on the sexual function of patients are currently unknown. Therefore, the objective of our study was to use a validated questionnaire, namely, the Female Sexual Function Index (FSFI), to compare the sexual function in patients with and without LAM avulsion after instrumental vaginal delivery. MATERIAL AND METHODS: This was a prospective observational study of 112 primiparous women after instrumental (vacuum or forceps) vaginal delivery. The obstetric and general characteristics of the population were studied. At 6 months postpartum, the contraceptive method used and the occurrence of LAM avulsion (using four-dimensional transperineal ultrasound) were determined, and the FSFI was administered. RESULTS: A total of 100 patients (62 without avulsion and 38 with avulsion) completed the study. Thirty-eight (38%) were diagnosed with avulsion (42.1% after Kielland forceps delivery, 57.9% after Malmström vacuum delivery; P = .837). Women with LAM avulsion had significantly lower scores for desire (2.9 ± 1.2 vs 3.4 ± 1.1; P = .049), arousal (2.8 ± 1.7 vs 3.6 ± 1.4; P = .014), lubrication (2.3 ± 1.4 vs 3.0 ± 1.2; P = .011), orgasm (2.6 ± 1.6 vs 3.3 ± 1.2; P = .006) and satisfaction (3.1 ± 1.8 vs 3.9 ± 1.5; P = .051) than did women without LAM avulsion. The overall FSFI score was lower in patients with avulsion (16.7 ± 8.9 vs 20.7 ± 6.9, P = .033). These results were obtained after controlling for confounders (delivery mode, induced labor, birthweight, perineal tears, avulsion degree, contraceptive method and group assignment for the parent study) in the multivariate analysis (F = 4.974, P = .001). CONCLUSIONS: Patients with LAM avulsion present a higher degree of sexual dysfunction compared wiith patients without avulsion at 6 months after instrumental vaginal delivery.

Prediction of spontaneous vaginal delivery in nulliparous women with a prolonged second stage of labor: the value of intrapartum ultrasound.

BACKGROUND: A limited number of studies have addressed the role of intrapartum ultrasound in the prediction of the mode of delivery in women with prolonged second stage of labor. OBJECTIVE: The objective of the study was to evaluate the role of transabdominal and transperineal sonographic findings in the prediction of spontaneous vaginal delivery among nulliparous women with prolonged second stage of labor. STUDY DESIGN: This was a 2-center prospective study conducted at 2 tertiary maternity units. Nulliparous women with a prolonged active second stage of labor, as defined by active pushing lasting more than 120 minutes, were eligible for inclusion. Transabdominal ultrasound to evaluate the fetal head position and transperineal ultrasound for the measurement of the midline angle, the head-perineum distance, and the head-symphysis distance were performed in between uterine contractions and maternal pushes. At transperineal ultrasound the angle of progression was measured at rest and at the peak of maternal pushing effort. The delta angle of progression was defined as the difference between the angle of progression measured during active pushing at the peak of maternal effort and the angle of progression at rest. The sonographic findings of women who had spontaneous vaginal delivery vs those who required obstetric intervention, either vacuum extraction or cesarean delivery, were evaluated and compared. RESULTS: Overall, 109 were women included. Spontaneous vaginal delivery and obstetric intervention were recorded in 40 (36.7%) and 69 (63.3%) patients, respectively. Spontaneous vaginal delivery was associated with a higher rate of occiput anterior position (90% vs 53.2%, P < .0001), lower head-perineum distance and head-symphysis distance (33.2 ± 7.8 mm vs 40.1 ± 9.5 mm, P = .001, and 13.1 ± 4.6 mm vs 19.5 ± 8.4 mm, P < .001, respectively), narrower midline angle (29.6° ± 15.3° vs 54.2° ± 23.6°, P < .001) and wider angle of progression at the acme of the pushing effort (153.3° ± 19.8° vs 141.8° ± 25.7°, P = .02) and delta-angle of progression (17.3° ± 12.9° vs 12.5° ± 11.0°, P = .04). At logistic regression analysis, only the midline angle and the head-symphysis distance proved to be independent predictors of spontaneous vaginal delivery. More specifically, the area under the curve for the prediction of spontaneous vaginal delivery was 0.80, 95% confidence interval (0.69-0.92), P < .001, and 0.74, 95% confidence interval (0.65-0.83), P = .002, for the midline angle and for the head-symphysis distance, respectively. CONCLUSION: Transabdominal and transperineal intrapartum ultrasound parameters can predict the likelihood of spontaneous vaginal delivery in nulliparous women with prolonged second stage of labor.