The Creation and Circulation of Evidence and Knowledge in American Medicine through the Lens of the "Husband's Stitch".

Physicians in the twentieth century routinely used episiotomy-a cut made during childbirth-to better facilitate labor, using the evidence of their experiences that it was useful. But physicians were not alone in producing evidence regarding episiotomy and its repair. Here I consider how three groups-male physicians, husbands, and laboring women-were involved in creating evidence and circulating knowledge about episiotomies, specifically, the intention of its repair, the so-called "husband's stitch," to sexually benefit men. By doing so I seek to consider the meanings of evidence within medicine, evidence as a basis for challenging the hegemony of medicine by lay women, and how medical knowledge is produced and shared among physicians and non-physicians.

Lateral episiotomy or no episiotomy in vacuum assisted delivery in nulliparous women (EVA): multicentre, open label, randomised controlled trial.

OBJECTIVE: To assess the effect of lateral episiotomy, compared with no episiotomy, on obstetric anal sphincter injury in nulliparous women requiring vacuum extraction. DESIGN: A multicentre, open label, randomised controlled trial. SETTING: Eight hospitals in Sweden, 2017-23. PARTICIPANTS: 717 nulliparous women with a single live fetus of 34 gestational weeks or more, requiring vacuum extraction were randomly assigned (1:1) to lateral episiotomy or no episiotomy using sealed opaque envelopes. Randomisation was stratified by study site. INTERVENTION: A standardised lateral episiotomy was performed during the vacuum extraction, at crowning of the fetal head, starting 1-3 cm from the posterior fourchette, at a 60° (45-80°) angle from the midline, and 4 cm (3-5 cm) long. The comparison was no episiotomy unless considered indispensable. MAIN OUTCOME MEASURES: The primary outcome of the episiotomy in vacuum assisted delivery (EVA) trial was obstetric anal sphincter injury, clinically diagnosed by combined visual inspection and digital rectal and vaginal examination. The primary analysis used a modified intention-to-treat population that included all consenting women with attempted or successful vacuum extraction. As a result of an interim analysis at significance level P<0.01, the primary endpoint was tested at 4% significance level with accompanying 96% confidence interval (CI). RESULTS: From 1 July 2017 to 15 February 2023, 717 women were randomly assigned: 354 (49%) to lateral episiotomy and 363 (51%) to no episiotomy. Before vacuum extraction attempt, one woman withdrew consent and 14 had a spontaneous birth, leaving 702 for the primary analysis. In the intervention group, 21 (6%) of 344 women sustained obstetric anal sphincter injury, compared with 47 (13%) of 358 women in the comparison group (P=0.002). The risk difference was -7.0% (96% CI -11.7% to -2.5%). The risk ratio adjusted for site was 0.47 (96% CI 0.23 to 0.97) and unadjusted risk ratio was 0.46 (0.28 to 0.78). No significant differences were noted between groups in postpartum pain, blood loss, neonatal outcomes, or total adverse events, but the intervention group had more wound infections and dehiscence. CONCLUSIONS: Lateral episiotomy can be recommended for nulliparous women requiring vacuum extraction to significantly reduce the risk of obstetric anal sphincter injury. TRIAL REGISTRATION: ClinicalTrials.gov NCT02643108.

The impact of selective episiotomy on maternal short-term morbidity: a retrospective study.

BACKGROUND: The aim is to investigate the risk of short-term maternal morbidity caused by the selective clinical use of episiotomy (rate < 0.02), and to compare the risk of severe perineal tears with the statewide risk. METHODS: In this retrospective cohort study, we investigated the effect of selective episiotomy on the risk of severe perineal tears and blood loss in singleton term deliveries, using propensity scores with inverse probability weighting. RESULTS: This study included 10992 women who delivered vaginally between 2008-2018. Episiotomy was performed in 171 patients (1.55%), three of whom (1.75%) experienced severe perineal tears compared to 156 (1.44%) in the control cohort. The adjusted odds ratio of severe perineal tears was 2.06 (95% confidence interval [CI]: 0.51, 8.19 with 0.3 p value). Multivariate linear regression showed that episiotomy increased blood loss by 96.3 ml (95% CI: 6.4, 186.2 with 0.03 p value). Episiotomy was performed in 23% (95% CI: 0.228, 0.23) of vaginal deliveries in the state of Hessen, with a risk of severe perineal tears of 0.0143 (95% CI: 0.0139, 0.0147) compared to 0.0145 (95% CI: 0.0123, 0.0168) in our entire cohort. CONCLUSIONS: Selective use of episiotomy does not increase the risk of higher-grade perineal tears. However, it may be associated with maternal morbidity in terms of increased blood loss.

An episiotomy is a cut between the vagina and the anus that may be performed by an obstetrician during childbirth and can result in increased blood loss or severe birth tears. In this study, we investigated the risks of both bleeding and severe tears caused by a highly selective local practice of episiotomies below 2% and compared the results with statewide data. The study included 10992 women who delivered between 2008­2018, 171 of whom underwent episiotomies according to the hospital's protocols. Having an episiotomy did not increase the likelihood of severe birthing tears but was associated with an increase in estimated blood loss. Therefore, although highly selective use of episiotomy is unlikely to cause more severe tears, it has the potential to worsen the mother's health by increasing blood loss.

Randomized controlled trial of the effectiveness of olive and black seed oil combination on pain intensity and episiotomy wound healing in primiparous women: A study protocol.

BACKGROUND: Episiotomy is associated with side effects, such as pain and wound infection. Additionally, discomfort after episiotomy affects the quality of life of both the mother and the baby. Medicinal herbs are one alternative method for the treatment of episiotomy wounds. This study will investigate the effectiveness of the combination of olive and black seed oil on pain intensity and the healing of episiotomy wounds in primiparous women. METHODS: This randomized clinical trial will be conducted on primiparous women who have had a normal delivery with an episiotomy. There are 3 groups in this study: one group will receive a combination of olive oil and black seed oil, another group will receive olive oil alone, and the use of oils will start 24 hours after delivery. Ten drops will be applied topically 3 times a day for 10 days. The third group (control) will receive only routine care. Data will be collected through a demographic characteristics questionnaire, REEDA (Redness, Edema, Ecchymosis, Discharge, and Approximation) Scale, and Visual Analog Scale. To determine and compare the effects of pharmaceutical interventions on pain intensity and episiotomy wound healing in the groups, an analysis of variance (ANOVA) test with repeated measurements will be used with SPSS version 22. DISCUSSION: The results of this study will show the effects of a combination of olive and black seed oil, as well as olive oil alone, on pain intensity and episiotomy wound healing in primiparous women. The positive effects observed in this trial with these oils could be valuable for women who have undergone an episiotomy.

Status of the midwifery workforce and childbirth services and the impact of midwife staffing on birth outcomes in China: a multicentre cross-sectional study.

OBJECTIVE: To investigate the status of the midwifery workforce and childbirth services in China and to identify the association between midwife staffing and childbirth outcomes. DESIGN: A descriptive, multicentre cross-sectional survey. SETTING: Maternity hospitals from the eastern, central and western regions of China. PARTICIPANTS: Stratified sampling of maternity hospitals between 1 July and 31 December 2021.The sample hospitals received a package of questionnaires, and the head midwives from the participating hospitals were invited to fill in the questionnaires. RESULTS: A total of 180 hospitals were selected and investigated, staffed with 4159 midwives, 412 obstetric nurses and 1007 obstetricians at the labour and delivery units. The average efficiency index of annual midwifery services was 272 deliveries per midwife. In the sample hospitals, 44.9% of women had a caesarean delivery and 21.4% had an episiotomy. Improved midwife staffing was associated with reduced rates of instrumental vaginal delivery (adjusted ß -0.032, 95% CI -0.115 to -0.012, p<0.05) and episiotomy (adjusted ß -0.171, 95% CI -0.190 to -0.056, p<0.001). CONCLUSION: The rates of childbirth interventions including the overall caesarean section in China and the episiotomy rate, especially in the central region, remain relatively high. Improved midwife staffing was associated with reduced rates of instrumental vaginal delivery and episiotomy, indicating that further investments in the midwifery workforce could produce better childbirth outcomes.

Obstetric Interventions Among Native and Migrant Women: The (Over)use of Episiotomy in Portugal.

Objective: Episiotomy, defined as the incision of the perineum to enlarge the vaginal opening during childbirth, is one of the most commonly performed surgical interventions in the world. We aimed to determine if migrant status is associated with episiotomy, and if individual characteristics mediate this association. Methods: We analyzed data from the Bambino study, a national, prospective cohort of migrant and native women giving birth at a public hospital in mainland Portugal between 2017 and 2019. We included all women with vaginal delivery. The association between migrant status and episiotomy was assessed using multivariable multilevel random-effect logistic regression models. We used path analysis to quantify the direct, indirect and total effects of migrant status on episiotomy. Results: Among 3,583 women with spontaneous delivery, migrant parturients had decreased odds of episiotomy, especially those born in Africa, compared to native Portuguese women. Conversely, with instrumental delivery, migrant women had higher odds of episiotomy. Disparities in episiotomy were largely explained by maternity units' factors, and little by maternal and fetal characteristics. Conclusion: Our results suggest non-medically justified differential episiotomy use during childbirth and highlight the importance of developing evidence-based recommendations for episiotomy use in a country with a high frequency of medical interventions during delivery.

Midwives' approach to the prevention and repair of obstetric perineal trauma in Spain.

AIM: Different clinical practice guidelines include recommendations on how to prevent and repair obstetric perineal trauma, as well as the use of episiotomy. To evaluate the variability in midwives' professional practices for preventing and repairing perineal trauma, as well as the professional factors that may be associated with the restrictive use of episiotomy. DESIGN: Observational cross-sectional study. METHODS: Three hundred five midwives completed an anonymous questionnaire developed by the authors and distributed across various midwifery scientific societies. The main outcomes measured were the frequencies of adopting specific practices related to perineal injury prevention and repair, episiotomy technique and restrictive episiotomy use (<10%). Odds ratios (OR) and adjusted odds ratios (aOR) with 95% confidence intervals were estimated. RESULTS: Intrapartum perineal massage was not normally used by 253 (83%) of midwives, and 186 (61%) applied compresses soaked in warm water to the perineum. Regarding episiotomy, there was a great deal of variability, noting that 129 (42.3%) adopted a restrictive use of this procedure, 125 (41%) performed it between 10% and 20%, while 51 midwives (16.7%) performed it in more than 20% of cases. In addition, 165 (54.1%) midwives followed an incision angle of 60º. Concerning tears, 155 (50.8%) usually sutured first-degree tears and 273 (89.5%) always sutured second-degree tears. Midwives attending home births (aOR = 6.5; 95% CI: 2.69-15.69), working at a teaching hospital (aOR = 3.69; 95% CI: 1.39-9.84), and the ones who recently completed their professional training (aOR = 3.58; 95% CI: 1.46-8.79) were significantly more likely to adopt a restrictive use of episiotomy. CONCLUSIONS: There is a significant variability in Spanish midwives' practices for preventing and repairing perineal tears. Moreover, the restrictive use of episiotomy is associated with midwives attending home births, working in teaching hospitals and having recent professional training. PATIENT OR PUBLIC CONTRIBUTION: No patient or public contribution.

Comparative study of postpartum sexual function: Second-degree tears versus episiotomy outcomes.

PURPOSE: The effects of episiotomy and second-degree tears on postpartum sexual function are key areas of enquiry in women's health research. Episiotomy and second-degree tears are common procedures and injuries that occur during childbirth. Understanding their impact on post-childbirth sexuality is crucial to women's overall well-being. This study aimed to examine the relationship between episiotomy, second-degree tears, and post childbirth sexuality. METHODS: A cross-sectional design was employed, including 83 women who gave birth to Cáceres in 2017. Participants were evaluated based on sociodemographic and sexual health factors. RESULTS: No significant differences were found in dyspareunia or sexual function between women who underwent episiotomies and those with second-degree tears. However, women who underwent episiotomies waited longer before resuming sexual activity after childbirth. Factors such as age, number of previous births, employment status, educational level, and breastfeeding status affected the timing and frequency of postpartum sexual activity. CONCLUSION: Dyspareunia negatively affects various aspects of sexual function. When comparing episiotomy and second-degree tears, their impacts on postpartum sexual function were similar. However, episiotomy delays the resumption of sexual activity. Sociodemographic factors significantly influence postpartum sexual health. These findings highlight the importance of individualised interventions and support for new mothers during the postpartum period to address potential sexual health concerns.

Evaluation of perineal wound healing and pain outcomes after low-angle mediolateral episiotomy in women undergoing vaginal childbirth: A systematic review and meta-analysis.

The efficacy of episiotomy, particularly the angle of incision in mediolateral episiotomies, remains a significant area of inquiry in obstetrics. This meta-analysis aimed to evaluate the impact of low-angle mediolateral episiotomy on perineal wound healing and pain outcomes in women undergoing vaginal childbirth. Adhering to PRISMA guidelines, a systematic review was conducted using the PICO framework. Studies were selected based on predefined inclusion and exclusion criteria, focusing on randomised controlled trials (RCTs) involving low-angle mediolateral episiotomies. Comprehensive literature searches were performed across major electronic databases including PubMed, Embase, Web of Science and Cochrane Library. Data extraction and quality assessments were meticulously carried out by independent reviewers, employing the Cochrane Collaboration's risk of bias tool. A total of 1246 articles were initially identified, with 8 articles meeting the strict inclusion criteria for the final analysis. The meta-analysis revealed significant heterogeneity among studies regarding postoperative pain (p < 0.0001, I2 = 77.5%), and employed a random-effects model. Results showed that low-angle episiotomies significantly reduced postoperative pain (OR = 0.27, 95% CI: 0.17-0.42, p < 0.001), and increased first-degree healing rates (OR = 2.95, 95% CI: 2.20-3.96, p < 0.001) compared to traditional angles. Sensitivity analyses confirmed the stability of these findings, and no significant publication bias was detected. The analysis suggests that low-angle episiotomies can potentially reduce postoperative perineal pain and enhance wound healing. However, the limited number and varying quality of the included studies warrant cautious interpretation of these results. Further well-designed studies are needed to corroborate these findings and guide clinical practice.

Exploring risk factors of pelvic organ prolapse at eastern of Democratic Republic of Congo: a case-control study.

BACKGROUND: Pelvic organ prolapse is a common debilitating condition worldwide. Despite surgical treatment, its recurrence can reach up to 30%. It has multiple risk factors, some of which are particular for a low-resource settings. The identification these factors would help to devise risk models allowing the development of prevention policies. The objective of this study was to explore risk factors for pelvic organ prolapse in a population in eastern Democratic Republic of Congo (DRC). METHODS: This was an unmatched case-control study conducted between January 2021 and January 2022. The sample size was estimated to be a total of 434 women (217 with prolapse as cases and 217 without prolapse as controls). Data comparisons were made using the Chi-Square and Student T tests. Binary and multivariate logistic regressions were used to determine associated factors. A p < 0.05 was considered significant. RESULTS: Variables identified as definitive predictors of pelvic organ prolapse included low BMI (aOR 2.991; CI 1.419-6.307; p = 0.004), home birth (aOR 6.102; CI 3.526-10.561; p < 0.001), family history of POP (aOR 2.085; CI 1.107-3.924; p = 0.023), history of birth without an episiotomy (aOR 3.504; CI 2.031-6.048; p = 0), height ≤ 150 cm (aOR 5.328; CI 2.942-9.648; p < 0.001) and history of giving birth to a macrosomic baby (aOR 1.929; IC 1.121-3.321; p = 0.018). CONCLUSIONS: This study identified that Body Mass Index and birth-related factors are definitive predictors of pelvic organ prolapse in a low-resource setting. These factors are potentially modifiable and should be targeted in any future pelvic organ prolapse prevention policy. Additionally, there seems to be a genetic predisposition for prolapse, which warrants further assessment in specifically designed large scale studies.

The REPAIR study: oral antibiotics to prevent infection and wound dehiscence after obstetric perineal tear-a double-blinded placebo controlled randomized trial.

BACKGROUND: Approximately 85% of women experience an obstetric tear at delivery and up to 25% subsequently experience wound dehiscence and/or infection. Previous publications suggest that intravenous antibiotics administrated during delivery reduces this risk. We do not know if oral antibiotics given after delivery can reduce the risk of wound dehiscence or infection. Our aim is to investigate whether three doses of oral antibiotics (amoxicillin 500 mg/clavulanic acid 125 mg) given after delivery can reduce the risk of wound dehiscence and infection in patients with a second-degree obstetric tear or episiotomy. METHODS: We will perform a randomized, controlled, double-blinded study including 221women in each arm with allocation 1:1 in relation to the randomization. The study is carried out at Department of Obstetrics & Gynecology, Herlev University Hospital, Copenhagen, Denmark. The women will be included after delivery if they have had a second-degree tear or episiotomy. After inclusion, the women will have a clinical follow-up visit after 1 week. The tear and healing will be evaluated regarding signs of infection and/or dehiscence. The women will again be invited for a 1-year clinical examination including ultrasound. Questionnaires exploring symptoms related to the obstetric tear and possible complications will be answered at both visits. Our primary outcome is wound dehiscence and/or wound infection, which will be calculated using χ2 tests to compare groups. Secondary outcomes are variables that relate to wound healing, as pain, use of painkillers and antibiotics, need for further follow-up, as well as outcomes that may be related to the birth or healing process, urinary or anal incontinence, symptoms of prolapse, female body image, and sexual problems. DISCUSSION: Reducing the risk of wound dehiscence and/or infection would decrease the number of control visits, prevent the need for longer antibiotic treatment, and possibly also decrease both short-term and long-term symptoms. This would be of great importance so the mother, her partner, and the baby could establish and optimize their initial family relation. TRIAL REGISTRATION: The conduction of this study is approved the 2/2-2023 with the EU-CT number: 2022-501930-49-00. CLINICALTRIALS: gov Identifier: NCT05830162.

Prescriptive and proscriptive lessons for managing shoulder dystocia: a technical and videographical tutorial.

This tutorial of the intrapartum management of shoulder dystocia uses drawings and videos of simulated and actual deliveries to illustrate the biomechanical principles of specialized delivery maneuvers and examine missteps associated with brachial plexus injury. It is intended to complement haptic, mannequin-based simulation training. Demonstrative explication of each maneuver is accompanied by specific examples of what not to do. Positive (prescriptive) instruction prioritizes early use of direct fetal manipulation and stresses the importance of determining the alignment of the fetal shoulders by direct palpation, and that the biacromial width should be manually adjusted to an oblique orientation within the pelvis-before application of traction to the fetal head, the biacromial width is manually adjusted to an oblique orientation within the pelvis. Negative (proscriptive) instructions includes the following: to avoid more than usual and/or laterally directed traction, to use episiotomy only as a means to gain access to the posterior shoulder and arm, and to use a 2-step procedure in which a 60-second hands-off period ("do not do anything") is inserted between the emergence of the head and any initial attempts at downward traction to allow for spontaneous rotation of the fetal shoulders. The tutorial presents a stepwise approach focused on the delivering clinician's tasks while including the role of assistive techniques, including McRoberts, Gaskin, and Sims positioning, suprapubic pressure, and episiotomy. Video footage of actual deliveries involving shoulder dystocia and permanent brachial plexus injury demonstrates ambiguities in making the diagnosis of shoulder dystocia, risks of improper traction and torsion of the head, and overreliance on repeating maneuvers that prove initially unsuccessful.

Maternal origin matters: Country of birth as a risk factor for obstetric anal sphincter injuries.

OBJECTIVE: Obstetric anal sphincter injuries (OASIS) are severe complications to vaginal births with potential long-term consequences. Maternal origin has been proposed to affect the overall risk, but the association and underlying explanation are uncertain. The objective was to assess the association between maternal country of birth and OASIS. METHODS: A Swedish nationwide cohort study including singleton term vaginal births during 2005-2016. Data were extracted from the Swedish Medical Birth Registry and Statistics Sweden. Modified Poisson regression analyses were performed to obtain crude and adjusted risk ratios (RRs). Adjustments were made in four cumulative steps. Sub-analyses were performed to investigate the risk of OASIS associated with female genital circumcision (FGC). RESULTS: In all, 988 804 births were included. The rate of OASIS in Swedish-born women was 3.5%. Women from East/Southeast Asia had an increased risk of OASIS (adjusted RR [aRR] 1.71, 95% confidence interval [CI] 1.60-1.83), as did women born in Sub-Saharan Africa (aRR 1.60, 95% CI 1.49-1.72). The risk remained significantly increased also after adjustment for maternal height. By contrast, women from South/Central America had a decreased risk of OASIS (aRR 0.65, 95% CI 0.56-0.76). FGC was associated with an increased risk of OASIS (aRR 3.05, 95% CI 2.60-3.58). Episiotomy appeared to have an overall protective effect (aRR 0.95, 95% CI 0.92-0.98), but not significantly more protective among women with female genital mutilation. CONCLUSIONS: Country of birth plays an important role in the risk of OASIS. Women from East/Southeast Asia and Sub-Saharan Africa are at significantly increased risk as compared with Swedish-born women, whereas women from South/Central America are at lower risk. FGC is also a significant risk factor for OASIS.

Primary perineal endometriosis - a case report and literature review.

Endometriosis is a common gynecological disease caused by the implantation of active endometrial cells outside the uterine cavity. In most cases, endometriosis occurs in the pelvic area, such as the ovary, Douglas' pouch, or uterine sacral ligament. Some rare cases of extrapelvic endometriosis can also occur in the perineum, urinary system, gastrointestinal tract, nervous system, chest, subcutaneous tissue, and skin. Endometriosis of the perineum is usually secondary to obstetric trauma, such as perineal laceration or episiotomy. To date, few cases of spontaneous perineal endometriosis have been reported. Herein, we report a rare case of spontaneous deep perineal endometriosis. Notably, the patient had typical symptoms of regular pain during menstruation with no history of delivery or perineal trauma. The patient recovered well after postoperative gonadotropin releasing hormone agonist injection.

Perineal injuries during vaginal birth in low-resource countries.

Birth related perineal trauma (BRPT) and obstetric anal sphincter injuries (OASIS) are leading causes of anal incontinence in women, which negatively impacts on their quality of life, resulting in low self-esteem and abandonment. In low resource countries (LRC), the true incidence is not known and since most births are unattended or occur in community-based health care systems, one can anticipate that it is a significant problem. Dissemination of information to women, education of traditional birth attendants, improvement of resources and transport, and training of health professionals on the detection and appropriate surgical management of these injuries will reduce morbidity and improve outcome. Intrapartum measures such as controlled head descent and perineal support, correct episiotomy techniques and selective use of instruments to assist vaginal births is pivotal in avoiding these injuries. Policy makers should prioritize maternity care in LRC, and research is urgently needed to address all aspects of BRPT.

The severity of second-degree perineal tears and perineal pain during three months postpartum: A prospective cohort study.

BACKGROUND: Second-degree perineal tears are common and can vary widely in the extent of tissue trauma. Therefore, a better understanding of perineal pain based on tissue trauma severity in second-degree tears is needed. AIM: The primary aim of this study was to assess differences in perineal pain according to the severity of perineal tears, with a focus on subcategories of second-degree tears, during the first three months postpartum. The secondary aim was to assess the use of pain medication and breastfeeding patterns according to the severity of the second-degree tears. METHODS: In this observational cohort study, nulli- and multiparous women with singleton pregnancies were included during pregnancy. After birth, perineal tears were classified using the latest international classification system. In addition, second-degree tears were subcategorised according to percentage of damage to the perineum (<50 %=2A,>50 % but less than entire perineum=2B, affecting entire perineum, anal sphincter not involved=2C). Perineal pain, use of pain medication and breastfeeding patterns were assessed during a phone interview seven to ten days postpartum and through an electronic questionnaire three months postpartum. FINDINGS: Out of 880 vaginal births, 852 participants completed the phone interview and 715 answered the electronic questionnaire. During the first three months postpartum, women with 2C-tears reported statistically significantly higher pain scores and more frequent use of pain medication compared to women with 2A-tears. There was no statistically significant difference between the number of participants not breastfeeding between second-degree tear subcategories. CONCLUSION: Women with 2C-tears reported higher perineal pain scores and more use of pain medication compared to those with less severe tears during three months postpartum.

Variation in Episiotomy Use Among Nulliparous Individuals by Maternity Care Provider and Associated Rates of Obstetric Anal Sphincter Injury.

OBJECTIVES: To quantify variation in the association between episiotomy and obstetric anal sphincter injury (OASI) by maternity care provider in spontaneous and operative vaginal deliveries (SVDs and OVDs). METHODS: Population-based retrospective cohort study of vaginal, term deliveries among nullipara in Canada (2004-2015). Adjusted rate ratios (ARRs) and 95% CIs were estimated using log-binomial regression to quantify the associations between episiotomy and OASI, stratified by care provider (obstetrician [OB], family physician [FP], or registered midwife [RM]) while adjusting for potential confounders. RESULTS: The study included 631 642 deliveries. Episiotomy use varied by provider: among SVDs, the episiotomy rate was 19.6%, 14.4%, and 8.4% in the OB, FP, and RM groups, respectively. The rate of OASI was higher among SVDs with versus without episiotomy (5.8% vs 4.6%). Conversely, OASI occurred less frequently in operative vaginal deliveries with episiotomy (15.3%) compared with those without (16.7%). In all provider groups, the ARR for OASI was increased with episiotomy in SVD and decreased with episiotomy with forceps delivery. No differences in these associations were observed by provider except among vacuum delivery (ARR with episiotomy vs. without, OB: 0.88, 95% CI 0.84-0.92; FP: 0.89, 95% CI 0.83-0.96, RM: 1.22, 95% CI 1.02-1.48). CONCLUSIONS: In nullipara, irrespective of maternity care provider, there is a positive association between episiotomy and OASI among SVDs and an inverse association between episiotomy and deliveries with forceps. The relationship between episiotomy and OASI is modified by maternity care providers among vacuum deliveries.