Obstetric Anal Sphincter Injuries Research Articles

Birthweight difference between deliveries and the risk of obstetric anal sphincter injury in parous women.

While obstetric anal sphincter injury (OASI) is less frequent in parous compared to nulliparous women, it remains a major concern affecting quality of life of women worldwide. The aim of this study was to evaluate the association between birthweight (BW) difference between deliveries and risk of OASI in parous women. We performed a retrospective case-control study including parous women with at least one previous vaginal delivery who were diagnosed with OASI. The control group consisted of parous women who did not have OASI during vaginal delivery. Controls were matched in a 1:2 ratio by year of birth, maternal age, and parity. Medical history, obstetric background, and current labor-related data were compared. Further univariate and multivariable analyses were performed, assessing for risk factors for OASI. One hundred eight parous women who had a diagnosis of OASI and a control group of 216 parturients who delivered without OASI were included in the final analysis. Differences between the current BW and the preceding and maximal previous BW were evaluated. There were significantly higher rates of women who had a larger neonate with > 500 g difference between the current and previous BW in the OASI group than in those with no OASI (28.7% vs. 12.30%, respectively; p < 0.001). Following a multivariable analysis for the dependent parameter of OASI, the following parameters were found to be independently associated with OASI outcome: previous operative vaginal delivery, BW ≥ 90th percentile, and current BW ≥ 500 g compared to previous maximal BW. In parous women, neonatal BW increase between deliveries of > 500 g is associated with OASI.

When does oasis cause de novo pelvic floor dysfunction? role of the surgeon's skills.

Introduction and hypothesisMinorly skilled gynecologists are less likely to repair obstetric anal sphincter injuries (OASIS), and this can lead to higher rate of de novo onset of pelvic floor dysfunction (PFD). The aim of this study was to understand the impact of surgeon skills in OASIS repair on de novo incidence of PFDs.MethodsAn observational prospective cohort study performed between January 2019 and December 2020. We included 116 women with OASIS. At 6-weeks from delivery, women were divided into two groups in relation to the onset of PFDs. Characteristics were compared; categorical and continuous variables were assessed with chi-squared test and the Mann–Whitney rank-sum test respectively. Factors involved in PFDs development were analysed with explorative univariate analysis; significant (p<0.05) or approaching significance (p≤0.10) variables were included in multivariable analysis.ResultsSeventy-six women (76/116; 65.5%) reported at least one PFD symptom and anal incontinence was the most prevalent (44.73%; 34/76). OASIS management by a skilled gynaecologist resulted protective for PFDs [aOR 0.33 (0.13-0.61)]. Skilled surgeon reported fewer PFDs than less skilled surgeon (4% vs 82.4%; p<0.0001). Operative delivery was more performed (32.5% vs 15.8%; p= 0.03) and severe OASIS resulted more prevalent (60% vs 17.1%; p<0.0001) among women without PDFs, even if these didn’t affect the incidence of de novo PFDs [aOR 1.03 (0.23-1.45) and 0.83 (0.13-1.45), respectively].ConclusionsSurgeons skilled in OASIS repair resulted the only protective factor for incidence of de novo PFDs in women with OASIS at 6 weeks of follow up. Improvement of training in OASIS repair is necessary.

What are the factors that may predict the severity of perineal tears in obstetric anal sphincter injuries and how are their outcomes? A 10-year retrospective analysis in a Southeast Asian population.

Obstetric anal sphincter injuries (OASIS) complicate around 1-2% of deliveries in low- and middle-income countries. Asians are twice more likely to suffer this complication. The 3c and 4th-degree perineal tears that involve the internal anal sphincter muscle and the anal mucosa have been reported to have a poorer outcome and higher risk of recurrence compared to less severe tears. A retrospective 10-year analysis of third- and fourth-degree perineal tears in a tertiary centrewas conducted. The maternal, neonatal factors and their respective outcomes after the repair of anOASIwere examined and compared between minor (3a and 3b perineal tears) and major anal sphincter tears (3c and 4th-degree perineal tears). Five hundred twentypatients with OASIS were included into the study. Birthweight ≥ 3.5 kg was significantly associated with having a major anal sphincter tear in this study population, OR 1.91 (95% CI 1.21-3.02), p = 0.006. There was no significant difference in having faecal or flatus incontinence after the repair; however, major anal sphincter tears appeared to be more complicated to repair compared to minor anal sphincter tears, requiring involvement of the consultant, p < 0.001. Neonatal birthweight ≥ 3.5 kg was the most significant factor in predicting the severity of OASIS in this study population. After appropriate repair, the rates of reported complications appeared similar between the two groups. However, significantly more expertise and resources were required for the repair of higher degree OASIS.

French guidelines for restrictive episiotomy during instrumental delivery were not followed by an increase in obstetric anal sphincter injury

The objective was to assess the influence of the French guidelines in favor of a restrictive use of episiotomy on both episiotomy and obstetric anal sphincter injury (OASI) rates during instrumental delivery. It was aulticenter study involving 193 maternities between 2000 and 2016. We included women with a singleton pregnancy, with cephalic presentation at 34 weeks of gestation or more who underwent an instrumental delivery. The study period was divided into three phases: 2000–2005 (reference) 2006–2011, and 2012–2016. We calculated the adjusted relative risk (aRR) of episiotomy and OASI and investigated for changes in episiotomy and OASI rates over time by using Prais–Winsten regression. We considered 96,035 deliveries. The episiotomy’s risk was lower in 2006–2011 (69.4%) and 2012–2016 (59.1%) compared to 2000–2005 (81.2%), respectively: aRR 0.93 [0.92–0.95] and 0.89 [0.87–0.90]. The OASI’s risk was higher in 2006–2011 (2.5%) and 2012–2016 (3.1%) compared to 2000–2005, respectively: aRR 1.30 [1.10–1.53]) and 1.57 [1.33–1.85]. However, Prais–Winsten regression showed no difference in the OASI rate during the study period. We observed a massive decrease in episiotomy use and a moderate increase in crude OASI’s rate but multivariate analysis failed to report an association between these outcomes.

Immediate postpartum assessment of the anal sphincter by endovaginal ultrasound: An experimental study

Obstetric anal sphincter injuries are frequently missed and carry a significant risk for the development of anal incontinence. Immediate postpartum endoanal ultrasound increases identification of these injuries but is rarely employed. We hypothesize that endovaginal ultrasound could be a feasible and easily available alternative sonographic tool to improve early diagnosis of anal sphincter tears. We conducted a prospective experimental study including 160 primiparous women. Shortly after vaginal delivery, patients underwent clinical and sonographic perineal examinations. We analyzed the feasibility of anal sphincter assessment by endovaginal ultrasound and its potential contribution in the early diagnosis of anal sphincter injuries. Sonographic assessment of the anal sphincter was analyzable for 136 patients (85.0%). Causes of non-analyzability included air artifacts (6.9%), lack of distinction between the external anal sphincter and surrounding tissues (9.4%) and distortion artifacts (9.4%). Patients in the non-analyzable ultrasound subgroup were less likely to have delivered in a dorsal lithotomy position (62.5% vs. 85.3 %) and more likely to have had an episiotomy (33.3% vs. 14.0%), and their risk of sphincter injury was more frequently classified as "improbable" on clinical examination (91.7% vs. 61.0%). Ultrasounds were analyzable for 96.4% of patients clinically reported as having "possible" or "certain" sphincter injuries. The incidence of anal sphincter injury was 16.9% for clinical observation and 20.0% with associated sonographic examination. Endovaginal ultrasound could be used as a complementary tool in assessment of the anal sphincter in high-risk patients. Its feasibility and easy availability make this technique a promising tool for improving the management of anal sphincter tears.

Modifiable and non-modifiable risk factors for obstetric anal sphincter injury in a Norwegian Region: a case\u2013control study

BackgroundObstetric anal sphincter injury (OASI) is a common and severe complication of vaginal delivery and may have short- and long-term consequences, including anal incontinence, sexual dysfunction and reduced quality of life. The rate of OASI varies substantially between studies and national birth statistics, and a recent meta-analysis concluded that there is a need to identify unrecognized risk factors. Our aim was therefore to explore both potential modifiable and non-modifiable risk factors for OASI.MethodsWe performed a case–control study in a single center maternity clinic in South-Eastern Norway. Data were extracted retrospectively from an institutional birth registry. The main outcome measure was the occurrence of the woman’s first-time 3rd or 4th degree perineal lesion (OASI) following singleton vaginal birth after 30 weeks’ gestation. For each woman with OASI the first subsequent vaginal singleton delivery matched for parity was elected as control. The study population included 421 women with OASI and 421 matched controls who gave birth during 1990–2002. Potential risk factors for OASI were assessed by conditional logistic regression analyses.ResultsThe mean incidence of OASI was 3.4% of vaginal deliveries, but it increased from 1.9% to 5.8% during the study period. In the final multivariate regression model, higher maternal age and birthweight for primiparous women, and higher birthweight for the multiparous women, were the only non-modifiable variables associated with OASI. Amniotomy was the strongest modifiable risk factor for OASI in both primi- (odds ratio [OR] 4.84; 95% confidence interval [CI] 2.60–9.02) and multiparous (OR 3.76; 95% CI 1.45–9.76) women, followed by augmentation with oxytocin (primiparous: OR 1.63; 95% CI 1.08–2.46, multiparous: OR 3.70; 95% CI 1.79–7.67). Vacuum extraction and forceps delivery were only significant risk factors in primiparous women (vacuum: OR 1.91; 95% CI 1.03–3.57, forceps: OR 2.37; 95% CI 1.14–4.92), and episiotomy in multiparous women (OR 2.64; 95% CI 1.36–5.14).ConclusionsAmniotomy may be an unrecognized independent modifiable risk factor for OASI and should be further investigated for its potential role in preventive strategies.

Is sonographic measurement of head-perineum distance useful to predict obstetrical anal sphincter injury in case of vacuum delivery?

Determine if head-perineum distance (HPD) measurement before vacuum extraction (VE) was predictive of an obstetric anal sphincter injury (OASIS) occurrence. Retrospective, bicentric (Lille and Poissy, France) cohort study conducted from January 2019 to June 2020. All VE in singleton pregnancies of ≥34weeks were included. HPD measurement was performed without compression of the tissues before each VE. The judgment criterion was the occurrence of an OASIS. Of 12 568 deliveries, VE was performed in 1093 (8.6%). Among these 1093 women undergoing VE, 675 (61.7%) with HPD measurement were included. OASIS was found in 6.5% of women (n=44; 95% CI 4.5-8.7). HPD was not associated with OASIS (38.5±12.6mm in women with OASIS vs 37.4±12.0mm in women without; adjusted OR [aOR] per 5mm increase=0.92; 95% CI 0.79-1.06). Increased HPD was associated with higher risk of sequential extraction (aOR=1.19; 95% CI 1.06-1.32), extraction duration >10min (aOR=1.12; 95% CI 1.02-1.23) and shoulder dystocia (aOR=1.20; 95% CI 1.03-1.40). Ultrasound-measured head-perineum distance does not predict the occurrence of obstetric anal sphincter injury during a VE. The interest of HPD is more about predicting the success or difficulty of VE rather its specific complications.

A step towards better audit: The Robson Ten Group classification system for outcomes other than cesarean section.

The Robson Ten Group Classification System is widely used for the audit of cesarean section (CS) rates. However, CS rate alone is a poor quality indicator and should be balanced with other obstetric endpoints. The aim of this study was to evaluate whether Swedish national data on obstetric outcomes other than CS, stratified by the Robson classification, could be analyzed in a useful way. All births in Sweden from 2017 through 2020 recorded in the nationwide Swedish Pregnancy Register were categorized using the Robson classification with subdivision of some groups. Five outcomes were explored: CS, operative vaginal delivery, postpartum hemorrhage, obstetric anal sphincter injury (OASIS) and Apgar score<7 at 5 minuteutes. Rates of each outcome and contribution of each group to the total outcome rate were calculated. The largest Robson groups were nulliparous and multiparous women with single-term cephalic pregnancies, unscarred uterus and spontaneous labor. Intrapartum CS rates were highest for multiple pregnancies, women with induced labor after previous CS, and nulliparous women with induced labor. Nulliparous women and multiparous women with a previous CS with attempted vaginal birth had the highest operative vaginal delivery and OASIS rates. The postpartum hemorrhage rate was highest for multiple pregnancies and transverse lie, followed by prelabor CS in nulliparous and multiparous women with single-term cephalic pregnancies and unscarred uterus. The highest rates of Apgar score<7 at 5 minute were observed in preterm deliveries, multiple pregnancies, transverse lie and breech presentation. The largest contribution to the total CS rate was made by women with previous CS delivered by prelabor CS, and nulliparous women with induced or spontaneous labor. The largest contribution to all other outcomes was made by nulliparous women with spontaneous or induced labor and, notably, multiparous women with spontaneous labor and unscarred uterus. The Robson classification provides a useful framework for analyzing CS rates alongwith rates of operative vaginal delivery, OASIS, postpartum hemorrhage and low Apgar score. Parallel interpretation of several outcomes allows a systematic and multidimensional audit, helpful for families and healthcare professionals, and can be used for comparisons, assessment of trends and subpopulations.

Comparison of two questionnaires to diagnose obstructive defecation syndrome during pregnancy and post-natally

Introduction and hypothesisObstructive defecation syndrome (ODS) is a common urogynaecology presentation. This study compares two questionnaires, the electronic Personal Assessment Questionnaire (e-PAQ), used in urogynaecology clinics, with the ODS-Score (ODS-S), a simple validated scoring system used in colorectal clinics for diagnosing ODS, to identify patients with an ODS-S cut-off ≥9.MethodsA total of 221 paired ODS-S and e-PAQ questionnaires were completed; 80 during the second trimester of pregnancy, 73 during the third and 68 post-natally, including women sustaining obstetric anal sphincter injury (OASI). e-PAQ score and ODS-S were compared and Pearson’s correlation coefficient calculated. Areas under the curve assessed the diagnostic ability of e-PAQ scores to identify patients with ODS-S of ≥9.ResultsThe e-PAQ and ODS-S scores showed a positive correlation in the second and third trimesters of pregnancy, post-natally and following OASI. Pearson’s correlation coefficient was calculated (0.77; p < 0.001, 0.79; p < 0.001, 0.66; p = 0.001 and 0.79; p < 0.001 respectively). An e-PAQ evacuatory domain score of ≥33 identified women with an ODS score of ≥9 with a sensitivity and specificity of 71% and 94% in the second trimester, 86% and 95% third trimester and 78% and 97% in the OASI group respectively. Area under the curve was >0.90 for all groups.ConclusionsComparison of e-PAQ evacuatory domain scores and ODS-S show a strong correlation, with an e-PAQ score of ≥33 promising for identifying women with an ODS score of ≥9, indicating ODS. This study will enable us to identify women during pregnancy and post-natally with ODS for whom early recognition and intervention may be beneficial.

Is there a role for transperineal ultrasound imaging of the anal sphincter immediately after primary repair of third degree tears?

ObjectiveWhen obstetric anal sphincter injuries are identified, it is crucial that the defects are repaired appropriately to achieve a better outcome. Although the presence of an intact anal sphincter is not the sole mechanism for maintaining continence, and not all women with an anal sphincter defect are symptomatic, there is an association between sphincter defects and anal incontinence. Our aim was to evaluate whether transperineal ultrasound (TPUS) is useful in assessing anal sphincter integrity immediately following primary repair of obstetric anal sphincter injuries (OASIs). Study DesignThis is a prospective observational study of women who sustained OASIs during their first vaginal delivery. Three dimensional (3D) TPUS was performed immediately after repair of OASIs to identify anal sphincter defects. A repeat TPUS was performed 12 weeks following repair. Results21 women sustained OASIs of whom 20 (95%) attended follow up. Eight (40%) had a grade 3a tear and 12 (60%) a 3b tear.8/20 (40%) women had residual external anal sphincter (EAS) defects identified by TPUS immediately after repair. Of these eight defects, six (75%) persisted at 12 weeks postpartum. No new defects were seen at follow up among the twelve women in whom no defect was seen immediately following the repair.Six residual EAS defects were found at 12 weeks postpartum. An EAS defect at 12 weeks postpartum was associated with anal incontinence (p = 0.04). Women with 3b tears were more likely to have anal incontinence (AI) and residual sonographic EAS defects when compared with 3a tears but this was not statistically significant. ConclusionsWomen who had no TPUS defect detected immediately following primary repair of OASIs, remained as such at 12 weeks postpartum. Of those in whom a defect was seen immediately after repair, it persisted in 75% of cases at 12 weeks. We believe that the value of TPUS immediately after repair appears to be limited and would need to be defined if it were to be considered for routine practice. Further research on its role immediately after repair of major tears (Grade 3C/4) is needed. In addition, performing ultrasound would require widespread training of obstetricians to develop expertise. This highlights the importance of adequate training of obstetricians in OASI repair.

Women's experiences of obstetric anal sphincter injury and physical therapy interventions - A qualitative study

BackgroundDuring childbirth, women may suffer perineal injuries that can lead to persistent disorders. No interview study has investigated women's experience of obstetric anal sphincter injuries (OASIS) and physical therapy rehabilitation process after the injury. ObjectiveTo describe women's experiences of OASIS and the physical therapy rehabilitation process. MethodsA qualitative study with an inductive approach based on semi-structured interviews was performed with 14 primi- and multi-parous women affected by OASIS. They had been sutured within 24 h and were recruited from a university hospital in Sweden. The interviews lasted between 35 and 66 min. Data were processed and analyzed using qualitative content analysis. ResultsThree main categories emerged from the analysis: The categories described experiences of a difficult time after the injury and physical therapy rehabilitation but also experiences of a safe follow-up. Moreover, experiences of that it wasn´t that bad after all when looking back. ConclusionRegardless of the extent of the injury, some women experienced a long and troublesome recovery with intense physical therapy rehabilitation, while other women felt that they fortunately got away lightly. Factors that can influence a woman's confidence in safely beginning pelvic floor muscle training at an early stage include individualizing when and how information about OASIS is provided. Meeting each woman's needs and wishes is emphasized by this study.

200 Association between maternal region of origin and birth and obstetric anal sphincter injury, by length of residence: A nation-wide cohort study

Introduction: Obstetric anal sphincter injury (OASI) is a severe obstetric complication, associated with long-term urogenital pain and dysfunction. Few studies have explored association between migration related characteristics and OASI. Our aim was to examine the association between maternal region of origin and birth, and OASI, by length of residence in Norway and paternal birthplace. Methods: This is a population-based cohort study on data from the Medical Birth Registry of Norway, including all primiparous women with a vaginal livebirth of a singleton cephalic foetus between 2008 and 2017 (n=188 658).

42 Effect of electronic and hybrid learning modalities for manual perineal support on incidence of obstetric anal sphincter injuries

Introduction: Obstetric anal sphincter injuries (OASIS) are the leading cause of female anal incontinence. Bimanual perineal support technique (bPST) help prevent OASIS. The study aims to test the effect of two different modalities for learning (bPST) on the incidence of OASIS. Methods: A quality-improvement-interventional study conducted in two hospitals between 1st June 2015 and 31st December 2016. A total of 1694 women were enrolled; all delivered vaginally at ≥24 gestational-weeks or with birthweight ≥1000gm.

Two midwives during the second stage of labour to reduce severe perineal trauma

The reported incidence of the most severe form of perineal trauma—obstetric anal sphincter injury—varies greatly; however, estimates from WHO suggest a global incidence of 4·0–6·6% from all vaginal deliveries.1,2 Obstetric anal sphincter injury is of major concern for women because it is associated with an increased risk of pelvic floor disorders, such as anal incontinence, urinary incontinence, pelvic organ prolapse, and sexual dysfunction. Pelvic floor disorders restrict women in their daily activities and have a negative impact on their quality of life.

Obstetric anal sphincter injury (oasis) and pelvic floor disorder awareness and knowledge among women in the second and third trimester of pregnancy

Approximately 55-80% of deliveries are complicated by some form of laceration, usually first or second degree. Some 10% of deliveries are affected by third or fourth degree lacerations which involve the anal sphincter complex. While there is no consensus on the classification of these injuries, the Obstetric Anal and Sphincter injury(OASIS) system is commonly used to classify third and fourth degree lacerations. These injuries can lead to long-term sequelae of pelvic floor disorders with implications on quality of life.

Maternal and neonatal morbidity after forceps or spatulas-assisted delivery in preterm birth

ObjectiveThe aim of this study was to assess perinatal morbidity associated with spatulas or forceps assisted delivery in preterm birth. Study designThis is a retrospective cohort study including all women with assisted deliveries on singleton pregnancy in cephalic presentation, before 37 weeks of gestation, in two tertiary care centers. We compared forceps-assisted deliveries with spatula-assisted deliveries. The main outcome was the rate of neonatal birth trauma. Secondary outcomes included other neonatal parameters, maternal outcomes and obstetric anal sphincter injuries. ResultsOut of 37 002 deliveries, 59 (0.2 %) preterm assisted deliveries with forceps and 111 (0.3%) preterm spatulas deliveries were included. The rate of neonatal birth trauma was low for both devices, without significant difference (3.4% in Forceps group vs 0.9% in Spatulas group, p = 0.28). The rate of episiotomy was 79.7% after forceps-assisted delivery and 48.6% for spatulas (p < 0.001). The rate of obstetric anal sphincter injuries was 1.7% and 2.7% respectively (p = 0,9). ConclusionThe rate of birth trauma was low in both forceps-assisted deliveries and spatula-assisted deliveries and was not significantly different between the two groups.

Obstetrics and gynecology residents' satisfaction and self-confidence after anal sphincter injury simulation-based workshop in Indonesia: a pre- and post-intervention comparison study.

PurposeObstetric anal sphincter injury is one of the most common complications during delivery. Simulation models with manikins can be used as an effective medical learning method to improve students’ abilities before encountering patients. The present study aimed to describe the development of an anal sphincter injury model and to assess residents’ satisfaction and self-confidence after a perineal repair workshop with an anal sphincter injury simulator in Indonesia.MethodsThis was a cross-sectional study with evaluation of outcomes before and after the workshop. We created a silicone-latex simulation anal sphincter injury model. Then, we validated this simulation and used it as a simulation model for the workshop. We asked residents about their satisfaction with repairing anal sphincter injuries using a simulation model and residents’ self-confidence when practicing anal sphincter injury repair.ResultsAll residents felt the simulation-based workshop was valuable (100%). Most of the scores for the similarity of the simulation model were good (about 8 out of maximum 10). The self-assessment of confidence was measured before and after the workshop. Overall self-confidence increased significantly after the workshop in identifying the external sphincter ani (EAS) (P=0.031), suturing the anal mucosa (P=0.001), suturing the internal sphincter ani (P=0.001), suturing the EAS (P<0.001), and evaluating the sphincter ani tone (P=0.016).ConclusionThe anal sphincter injury simulator improved residents’ self-confidence in identifying the EAS, suturing the anal mucosa, suturing the internal sphincter ani, suturing the EAS, and evaluating sphincter ani tone.

Under-classified obstetric anal sphincter injuries

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. 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. 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. 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 sonographic fetal head circumference measurement help predict obstetric anal sphincter injury?

To investigate whether sonographic fetal head circumference (sfHC) size assessed by ultrasound prenatally could help predict OASIS. This study is a retrospective cohort study between 2005 and 2016. Antenatal sfHC assessment, maternal demographics, and labor and delivery data were abstracted and compared in women with and without OASIS. Of 2057 pregnant women that had sfHC assessment, 121 (5.8%) had OASIS. In the unadjusted analysis, sfHC above the 90th centile was associated with OASIS (odds ratio [OR] 1.12; 95% confidence interval [CI] 1.02-1.23; P=0.015). When adjusted for gestational age at delivery, maternal age, race, prolonged second stage, body mass index, infant gender, and intrapartum oxytocin use, sfHC above the 90th centile remained significantly associated with OASIS (OR 1.13, 95% CI 1.00-1.27, P=0.050). In our cohort, sfHC above the 90th centile was associated with a greater risk of OASIS. As OASIS significantly impacts both short-term and long-term health outcomes, such as perineal pain, dyspareunia, and urinary and fecal incontinence, sfHC could be an additional prenatal marker to help clinicians counsel pregnant women about the risk of OASIS.

Obstetrical anal sphincter injury and unnecessary episiotomy are both associated with anal incontinence 8 years after childbirth: A nationwide database analysis.

To assess the relationship between anal incontinence (AI) 8years after childbirth and the occurrence of obstetrical anal sphincter injuries (OASIS) and/or performance of an episiotomy during childbirth. This is a nationwide database analysis performed on two national medico-administrative databases, including all the women aged 18years or older who delivered infants in France in 2012. The main outcome measure was AI in the 8years after delivery. Of the 163 443 perineal tears reported, 0.47% were grade 3 (n = 3173) and 0.08% were grade 4 (n = 579); 8938 women experienced AI (1.33%) and 261 women experienced severe AI (0.04%). Episiotomies performed in the absence of risk factors for OASIS were significantly associated with an increased risk of AI (odds ratio [OR] 1.59, 95% confidence interval [CI]1.49-1.69; P<0.001). Grade 3 and 4 OASIS also significantly increased the risk of AI and severe AI. Mediolateral episiotomy was preventive of OASIS when performed in women at risk (OR 0.26, 95% CI 0.23-0.30; P<0.001) but contributed to OASIS in the absence of risk (OR 2.18, 95% CI 1.98-2.40; P<0.001). OASIS present a risk factor for AI. Episiotomies could reduce the occurrence of OASIS, but they could also increase the risk of long-term AI in the absence of risk factors for OASIS.