Prevalence and factors associated with the perception of perineal laceration: a cross-sectional study with data from the Nascer no Brasil Survey, 2011 and 2012.

OBJECTIVE: To describe the prevalence of perineal laceration, based on the self-reported perception of postpartum women, and to analyze factors associated with its occurrence in Brazil. METHODS: This was a cross-sectional study conducted with 23,894 postpartum women, excluding twin pregnancies, cesarean sections, and births with episiotomies, between 2011 and 2012. Prevalence ratios (PR) and 95% confidence intervals (95%CI) of association between the event and maternal, fetus/newborn, obstetric and clinical management characteristics were estimated in hierarchical Poisson regression models. RESULTS: Out of 4,606 postpartum women, 49.5% (95%CI 46.1;42.9) self-reported perineal laceration. Being an adolescent (PR = 1.12; 95%CI 1.02;1.25), primipara (PR = 1.47; 95%CI 1.33;1.63), having had excessive gestational weight gain (PR = 1.17; 95%CI 1.07;1.29) and having undergone the Kristeller maneuver (PR = 1.18; 95%CI 1.08;1.29) increased the proportion of the outcome. CONCLUSION: The results found call for prenatal care and adjustments to childbirth care so as to be in accordance with current recommendations. MAIN RESULTS: Prevalence of self-reported perineal laceration was 49.5%. Being in the adolescent age group, primiparity, excessive gestational weight and the Kristeller maneuver were risk factors associated with the event. IMPLICATIONS FOR SERVICES: Studying self-reported prevalence of perineal laceration supports new care practices, highlights the prevention of risk factors considered modifiable and confirms the need to follow current guidelines. PERSPECTIVES: New national studies are needed comparing prevalence of self-reported perineal laceration with that recorded in medical records in order to support care practices and public obstetric policies.

[FETAL LACERATIONS DURING CESAREAN SECTION - AN INEVITABLE COMPLICATION].

INTRODUCTION: Cesarean section is the most prevalent in obstetrics and its rate is rising worldwide every year. Although this operation is considered safe, it is not free from complications. In the present review the topic of lacerations in the fetus during cesarean section is discussed. The rate of fetal lacerations during cesarean section is 0.79-1.9% of all cesareans. Several risk factors for this complication have been elaborated in the literature and are presented in this review. However, so far there is no proven method or technique that has been proven effective in the prevention of this complication. Fetal lacerations are not always identified in the operating room and are discovered later in the newborns department. Most lacerations occur on the fetal scalp and face, however, they can occur everywhere in the body of the fetus. Treatment is performed with adhesive medications or by surgical stitches. Normally, fetal lacerations are expressed later in life as a cosmetic problem but some may cause functional handicap of the affected organs. Every delivery that ends with this complication is followed by a lawsuit against the physicians involved in the case and almost always, the alleged physicians are found guilty. A possible solution to this problem is discussed in the present review.

Demographic, Etiological, and Clinical Characteristics of Eyelid Lacerations.

Objectives: To evaluate the demographic, etiological, and accompanying clinical factors in eyelid lacerations (EL). Materials and Methods: The records of patients who presented to our clinic between 2018 and 2022 with eyelid trauma were retrospectively reviewed. Age, gender, cause of injury, clinical findings, accompanying ocular findings, and additional complications were analyzed. Results: The study included 135 patients (106 male, 29 female) with a mean age of 37.0±18.6 years. Among the patients, 29 (21.4%) were 18 years old or younger, 93 (68.8%) were between 19 and 64 years old, and 13 (9.6%) were 65 years old or older. EL were most caused by various sharp objects in 44 patients (33%), blunt trauma in 40 patients (30%), falls in 30 patients (22%), and traffic accidents in 21 patients (15%). Fifteen eyes (11.1%) had foreign bodies at the wound site. Thirty patients (22.2%) (20 lower eyelid, 10 upper eyelid) had accompanying canalicular lacerations. Twenty-three (17%) patients had accompanying conjunctival lacerations, 14 (10.3%) had open-globe injury, 10 (7.4%) had corneal epithelial defects, 9 (6.6%) had intravitreal hemorrhage, 6 (4.4%) had hyphema, and 5 (3.7%) had retinal detachment. Four patients had lid notching and 1 patient (0.7%) had ectropion. Five patients (3.7%) required suturing. No additional complications were observed. Conclusion: EL are more commonly seen in young adulthood and in males. The most common mechanism of injury is impact by various objects. Eyelash margin and canalicular lacerations frequently accompany these injuries. Serious ocular pathologies such as hyphema and open-globe injury can accompany eyelid trauma.

[Lacrimal system trauma]. / Traumatologie lacrymale.

Among lacrimal system injuries, canalicular lacerations are at the top of the list. Men are more affected than women, but children are most likely to experience such trauma. The cause depends on the patient's age: in young children, there is a higher prevalence of animal bites (dogs and cats); in young adults, fights predominate, since motor vehicle accidents have become less common; in the elderly, falls are among the most frequent causes. Tetanus vaccination is required in all cases, but assessment for rabies exposure is necessary in the case of dog or cat bites. Diagnosis is very simple: it is based on examination or wound probing. Other head, facial, or ocular injuries must be excluded; for example, an injury to the globe must take precedence over a canalicular laceration. In the absence of an ocular injury, the canalicular wound should be managed surgically within 48hours under an operating microscope: identification of both severed ends of the injured canaliculus, suture of the severed canaliculus with monofilament suture, and appropriate lacrimal intubation if indicated. Other trauma to the lacrimal system, such as sharp or blunt trauma to the lacrimal sac or nasolacrimal duct, are much rarer.

The postnatal effects of perineal trauma on maternal psychological and emotional wellbeing: A longitudinal study.

OBJECTIVE: To examine the postnatal psychological health and parenting adjustment of primiparous women experiencing perineal trauma. STUDY DESIGN: Longitudinal cohort study assessing body image, perceptions of traumatic birth, psychological distress, perineal pain, impact upon parental tasks and mother-infant bonding at 6-12 weeks (n = 103) and 6-10 months postnatally (n = 91). Primiparous women were recruited following vaginal birth and perineal suturing in a UK-based maternity hospital. al. Comparisons made according to the objective classification of perineal trauma experienced; 1st/2nd degree tear, episiotomy, and Obstetric Anal Sphincter Injuries (OASI). RESULTS: At 6-12 weeks women with an episiotomy reported a more negative perception of their body image than those with OASI. Women with OASI or an episiotomy were more likely to have experienced birth as traumatic, and those with OASI reported more avoidance symptoms of post-traumatic stress and a greater negative impact on parenting tasks. At 6-10 months significantly more avoidance symptoms continued to be reported by those with OASI, whereas those with an episiotomy reported more anxiety related symptoms in general than those with OASI. CONCLUSIONS: OASI, whilst associated with traumatic birth and some early parenting impacts, may not be linked to general negative psychological outcomes when specialist routine follow-up care is provided. Psychological impacts for women with episiotomy may merit further input than currently provided. Consideration should be given with regards to widening the access to postnatal perineal care by extending the criteria for specialist follow up beyond those sustaining OASI.

Is water delivery a good idea to prevent obstetric anal sphincter injuries in low risk primiparae? An exploratory study in a Swiss public teaching hospital.

OBJECTIVE: Obstetric anal sphincter injuries are feared perineal injuries that are associated with increased pelvic floor disorders. The knowledge of influencing factors as the mode of delivery is therefore important. The aim of this study is to compare the rate of obstetric anal sphincter injuries in primiparae after water and bed deliveries. STUDY DESIGN: In this retrospective cohort study 3907 primiparae gave birth in water or on a bed in a Swiss teaching hospital. The diagnosis of obstetric anal sphincter injuries was confirmed by a consultant of obstetrics and gynecology and treated by them. The rates of these injuries after water and bed births were compared. Subgroup analysis was performed to detect possible associative factors, such as birth weight, episiotomy, use of oxytocin in first and second stage of labor. RESULTS: 1844 (47.2 %) of the primiparae had a water delivery and 2063 (52.8 %) a bed delivery. 193 (4.94 %) were diagnosed with obstetric anal sphincter injuries, of which 68 (3.7 %) had a water delivery and 125 (6.1 %) a bed delivery, p < 0.001. Subgroup analysis revealed that, in the first and second stage of labor, the rate of obstetric anal sphincter injuries with oxytocin was significantly lower in water than in bed deliveries; p = 0.025, p < 0.017, respectively. The rate of obstetric anal sphincter injuries in the birth weight or episiotomy subgroups did not reach significance. CONCLUSIONS: In a teaching hospital setting with standardized labor management, primiparae with a water delivery have the lowest risk for obstetric anal sphincter injuries.

Perineal lacerations and social media: can patients find reliable information on Instagram and TikTok?

INTRODUCTION AND HYPOTHESIS: Social media content related to patient experiences and education continues to grow. Information on how obstetric perineal lacerations are represented on social media is limited. Our goal is to characterize available social media content on obstetric perineal lacerations. METHODS: This is an IRB-exempt study using publicly available data on commonly searched topics about perineal lacerations to create a list of queries for Instagram and TikTok. The ten queries and "keyword" searches with the highest number of posts were identified from this list. The 50 most recent posts were reviewed for relevance, quality of content, and authorship. Topic-relevant posts were analyzed. RESULTS: The search yielded 427 posts on Instagram and 500 on TikTok. Instagram yielded more topic-relevant posts than TikTok (94.1% vs 44.8%). Almost 50% of posts were categorized as educational. Instagram identified more patient experience-related posts (29.6%) whereas TikTok provided more humorous content (26.3%). Patients produced 27.6% of content on Instagram and 43.3% on TikTok. Physical therapists produced 18.9% of posts on Instagram and 21.9% on TikTok. They constituted the largest group of health professionals to post overall. Physician-created educational content accounted for 10.3% of posts on Instagram and 6.0% on TikTok. CONCLUSIONS: Compared with TikTok, Instagram may be a more informative social media platform for educational or patient experience-related content. Given the paucity of physician-created content and given that only half of all posts are educational, providers should encourage social media engagement for community and networking purposes, while encouraging caution with regard to cosmetic products and advertisements.

Episiotomy practice in France and prevention of high-grade perineal tears at the time of operative vaginal delivery: a prospective multicentre ancillary cohort study.

INTRODUCTION AND HYPOTHESIS: Evidence suggests that episiotomies reduce the risk for obstetric anal sphincter injuries (OASIs) in operative vaginal deliveries (OVDs). However, there is limited evidence on the importance of episiotomy technique in this context. The primary objective of this study was to assess if an episiotomy suture angle >45° from the median line would be associated with a lower risk for OASIs at the time of OVD. METHODS: This was an ancillary study from the multicentre prospective cohort INSTRUMODA study. Of the 2,620 patients who had an OVD with a concomitant episiotomy between April 2021 and March 2022, a total of 219 fulfilled the inclusion criteria. Post-suturing photographs were used to assess episiotomy characteristics. RESULTS: Based on suture angles of ≤45° and >45° the study cohort was categorized into groups A (n = 155) and B (n = 64) respectively. The groups had comparable demographic and birth-related characteristics. The mean episiotomy length was significantly longer in group A than in group B (3.21 cm vs 2.84 cm; p = 0.009). Senior obstetricians performed more acute angled episiotomies than junior residents (p = 0.016). The total prevalence of OASIS was 2.3%, with no significant difference in rate of OASI between the two study groups. Birthweight was significantly higher in OASI births (p = 0.018) and spatula-assisted births were associated with higher risk for OASIs than ventouse or forceps (p = 0.0039). CONCLUSIONS: This study did not demonstrate a significant reduction in risk for OASI at the time of OVD when the episiotomy suture angle was >45° from the median line. However, these results should be interpreted with caution owing to the low prevalence of OASIs in our cohort.

Complications 8 weeks after an obstetric second-degree perineal laceration in relation to body mass index.

INTRODUCTION AND HYPOTHESIS: How body mass index (BMI) affects pelvic floor function after a second-degree perineal laceration is unknown. The hypothesis of this study is that pelvic floor dysfunction and complications after an obstetric second-degree perineal laceration are more common in women with a higher BMI 8 weeks postpartum. METHODS: This register-based cohort study includes 10,876 primiparous women with an obstetric second-degree perineal laceration between 2014 and 2021. Data were retrieved from the Swedish Perineal Laceration Registry. Outcomes in relation to maternal BMI were urinary incontinence (UI), anal incontinence (AI) and common complications attributable to the laceration. Uni- and multivariate logistic regressions were used for comparison between normal weight (BMI < 24.9, reference), overweight (25.0-29.9) and obese (≥ 30) women. RESULTS: Multivariate analyses showed an increased risk for UI in both overweight and obese women compared to normal-weight women 8 weeks after a second-degree perineal laceration with an adjusted odds ratio (aOR) of 1.21 (CI 1.02-1.44) and 1.27 (CI 1.13-1.58) respectively. Overweight and obese women had a decreased risk for AI (aOR 0.81, CI 0.68-0.96; aOR 0.72, CI 0.57-0.90 respectively) compared with normal-weight women. No significant differences were found in the univariate analyses over BMI strata concerning complications after perineal laceration. CONCLUSIONS: Primiparous overweight and obese women report less AI and more UI than normal-weight women 8 weeks after a second-degree perineal laceration. No differences were found regarding complications. These findings are new and merit further study to find potential preventive factors and interventions after a second-degree perineal laceration.

The infection, cervical and perineal lacerations in relation to postpartum hemorrhage following vaginal delivery induced by Cook balloon catheter.

OBJECTIVE: To identify whether infection, cervical laceration and perineal laceration are associated with postpartum hemorrhage in the setting of vaginal delivery induced by Cook balloon catheter. MATERIALS AND METHODS: The retrospective study included 362 women who gave birth vaginally at or beyond 37 weeks of gestation with a diagnosis of postpartum hemorrhage between February 2021 to May 2022, of which including 216 women with induction of labor (Cook balloon catheter followed by oxytocin or oxytocin) and 146 women with spontaneous delivery. Risk factors for postpartum hemorrhage were collected and compared. RESULTS: 362 women were divided into three groups, group 1 with spontaneous delivery, group 2 with oxytocin, group 3 with Cook balloon catheter followed by oxytocin. There was no significant difference in incidence of infection within three groups (P > 0.05). The rate of cervical laceration and perineal laceration was significantly higher in group 3 compared with groups 2 and 1 (P < 0.05); Multivariate logistic regression analysis found that compared with group 1, either group 3 or group 2 was associated with increased risks of cervical laceration and perineal laceration (P < 0.05), and compared with group 2, group 3 was not associated with increased risks of cervical laceration and perineal laceration (P > 0.05). CONCLUSION: Infection, cervical laceration and perineal laceration are identified not to be independent risk factors for postpartum hemorrhage for women undergoing labor with Cook balloon catheter; Cervical laceration and perineal laceration increase the risk of postpartum hemorrhage in women with labor induction.

Family medicine physician identification of obstetric lacerations: a US national survey.

INTRODUCTION AND HYPOTHESIS: We evaluated family medicine obstetric providers' identification and categorization of vaginal delivery lacerations in the USA. We hypothesized that there would be inaccuracy in family medicine physicians' identification of vaginal delivery injuries, similar to our previous studies of midwives and obstetricians (OBs). METHODS: We included clinically active physicians who attended deliveries within 2 years and evaluated their identification and categorization of delivery lacerations using descriptive text and visual images. We asked about their education on this topic and how they document lacerations in the labor and delivery record. RESULTS: We analyzed 250 completed responses (70% of opened surveys). Fifty-five percent of respondents characterized their obstetric laceration training as "good" or "excellent" and half previously had education on obstetric lacerations. The median accuracy overall for the classification and identification of perineal lacerations was 78% (IQR 56-91%). Respondents frequently mischaracterized nonperineal lacerations. Few respondents (36%) reported using the third-degree injury subclassification system. In adjusted analysis, the highest scoring respondents were board certified in family medicine, with fewer years in practice, and a higher obstetric volume. CONCLUSIONS: Obstetric laceration diagnoses may be inaccurate, which could influence perinatal quality and patient outcomes. We found gaps in knowledge similar to previous reports on midwives and obstetricians in the USA. These data suggest a need for increased education and training on obstetric injuries, perhaps especially for physicians with less obstetric activity. Improved categorization and identification of vaginal delivery trauma can impact management and improve women's postpartum care and long-term pelvic floor outcomes.

A systematic review and a meta-analysis on the incidence of obstetric anal sphincter injuries during vaginal delivery.

AIM: The incidence of obstetric anal sphincter injuries (OASIS) has increased in the past two decades despite improved awareness of the risk factors. This study aimed to define the incidence of OASIS in women with different features (instrumental delivery or other variables). METHODS: A systematic review was conducted on articles reporting the incidence of OASIS. This review aims to examine the association of instrumentation and OASIS by performing a formal systematic review of the published literature. Databases used for the research were MEDLINE, Embase, CINAHL and 'Maternity and infant care' databases. RESULTS: Two independent reviewers screened the selected articles. 2326 duplicates were removed from the total of 4907 articles. The remaining 2581 articles were screened for title and abstract. 1913 articles were excluded due to irrelevance. The remaining 300 were screened as full text. Primiparity associated with the use of forceps were the features associated with the highest incidence of OASIS in the selected articles (19.4%). OASIS in all women had an overall incidence of 3.8%. The incidence of OASIS in all women by geographical region was the highest (6.5%) in North America. CONCLUSIONS: There are various factors that impact on the incidence of OASIS and the combination of some of these, such as the use of forceps in primiparas, resulted in the highest incidence of OASIS. The lack of international consensus is limiting the improvements that can be done to reduce OASIS rates and improve best clinical practice.

Fractured sternal wire causing a cardiac laceration.

BACKGROUND: Hemopericardium is a serious complication that can occur after cardiac surgery. While most post-operative causes are due to inflammation and bleeding, patients with broken sternal wires and an unstable sternum may develop hemopericardium from penetrating trauma. CASE PRESENTATION: We present the case of a 62-year-old male who underwent triple coronary bypass surgery and presented five months later with sudden anterior chest wall pain. Chest computed tomography revealed hemopericardium with an associated broken sternal wire that had penetrated into the pericardial space. The patient underwent a redo-sternotomy which revealed a 3.5 cm bleeding, jagged right ventricular laceration that correlated to the imaging findings of a fractured sternal wire projecting in the pericardial space. The laceration was repaired using interrupted 4 - 0 polypropylene sutures in horizontal mattress fashion between strips of bovine pericardium. The patient's recovery was uneventful and he was discharged on post-operative day four without complications. CONCLUSION: Patients with broken sternal wires and an unstable sternum require careful evaluation and management as these may have potentially life-threatening complications if left untreated.

Is There Still a Place for Forceps Delivery in Modern Obstetrics?

BACKGROUND: Nowadays, we are witnessing a decrease of vaginal instrumental deliveries and continuous increase of caesarean section rate. However, proper identification of possibility of execution, indications for instrumental delivery and their skilful use may improve the broadly understood maternal and neonatal outcomes. The aim of this study is to present prevalence, risk factors, indications and outcomes of forceps deliveries among the patients at Department of Perinatology, Lodz. MATERIAL AND METHODS: A retrospective study was conducted at the Department of Perinatology, Medical University of Lodz. The study included forceps deliveries carried out between January 2019 and December 2022. Total number of 147 cases were analysed in terms of indications for forceps delivery and maternal and neonatal outcomes such as vaginal - or cervical - laceration, postpartum haemorrhage, perineal tear, newborn injuries, Apgar score, umbilical cord blood gas analysis, NICU admission and cranial ultrasound scans. RESULTS: The prevalence of forceps delivery was 2.2%. The most common indication for forceps delivery was foetal distress (81.6%). Among mothers, the most frequent complication was vaginal laceration (40.1%). Third-and fourth-degree perineal tears were not noted. Regarding neonatal outcomes, Apgar score ≥ 8 after 1st and 5th minute of life received accordingly 91.2% and 98% of newborns. Only 8.8% experienced severe birth injuries (subperiosteal haematoma, clavicle fracture). CONCLUSIONS: Although foetal distress is the most common indication for forceps delivery, the vast majority of newborns were born in good condition and did not require admission to NICU. Taking into consideration high efficacy and low risk of neonatal and maternal complications, forceps should remain in modern obstetrics.

Applying Vernix Caseosa for Accidental Foetal Lacerations during Caesarean Delivery: A Case Series.

The caesarean section is a frequently performed method of delivery. Although the caesarean section is a low-risk and safe surgery, there is an increase in maternal and infant morbidity and mortality due to caesarean delivery. One of the most common infant morbidities is foetal laceration. Caesarean delivery has a 1-2% risk of laceration to the foetus. Various methods have been proposed to deal with laceration wounds. Studies have been conducted on vernix caseosa, which can heal wounds on the skin. This case series report aims to demonstrate that vernix caseosa application is a wound healing method that is highly effective, costless, and of immediate availability.

Delayed Presentation of Popliteal Artery Laceration Mimicking Baker Cyst After Arthroscopic Meniscectomy: A Case Report.

CASE: We report a case of delayed presentation of popliteal artery laceration after arthroscopic meniscectomy. Three weeks after the procedure, the patient developed severe calf pain, swelling over the popliteal fossa, and foot drop, despite a normal initial postoperative period. Clinical examination and radiological investigations suggested a massive hematoma in the popliteal fossa. A decision was made to explore the popliteal artery and drain the hematoma after consultation with the vascular surgeon. A laceration was noted, and it was repaired. CONCLUSION: Orthopaedic surgeons should maintain a high index of suspicion regarding the possibility of this postoperative complication, especially after an arthroscopic meniscectomy.

One-year follow-up after standardized perineal reconstruction in women with deficient perineum after vaginal delivery.

INTRODUCTION: Perineal tears are common after childbirth and, if not surgically repaired, they may result in a deficient perineum that can cause symptoms of pelvic floor dysfunction. Perineal reconstruction aims to restore the perineal body and increase the support of the pelvic floor. The objective of the present study was to estimate symptom reduction after perineal reconstruction in patients with deficient perineum after vaginal delivery and to compare outcomes between participants with or without concomitant levator ani muscle deficiency. MATERIAL AND METHODS: Participants presenting at the Karolinska Pelvic Floor Center with symptoms of deficient perineum at least 1 year after vaginal birth were invited to the study. Inclusion criteria were a visible perineal scar and confirmed anatomic defect. Levator ani defects were assessed using the Levator Ani Deficiency score. A perineal reconstruction was performed in a standardized way. Subjective symptoms were evaluated using the validated "Karolinska Symptoms After Perineal Tear Inventory" at baseline and 1-year follow-up. A score difference in the symptom of an acquired sensation of a wide vagina was the primary outcome. Results were stratified by the presence or absence of a levator ani deficiency. RESULTS: A perineal reconstruction was performed in 131 patients and 128 patients completed the Karolinska Symptoms After Perineal Tear Inventory at baseline and 119 at follow-up. Median age was 36.1 (interquartile range [IQR] 7.9), median body mass index 22.3 (IQR 5.1) and a median of two vaginal deliveries. Fifty-four women (41.2%) had a levator ani deficiency. The mean score reduction for the item "Do you feel that your vagina is too wide/loose?" was -1.56 (SD 0.96; P < 0.001) from a mean score of 2.75 (maximum 3) at baseline. The mean total score reduction was -9.1 points (SD 5.3; P < 0.001) from a mean score of 18.4 (maximum 33) points at baseline. There were no significant differences between groups when stratifying by levator ani deficiency. CONCLUSIONS: Our results show that perineal reconstructive surgery significantly decreases symptoms of deficient perineum after vaginal delivery. A concomitant levator ani defect does not affect the symptom reduction of an acquired sensation of a wide vagina or the total score reduction after surgery.

Prediction models for perineal lacerations during childbirth: A systematic review and critical appraisal.

BACKGROUND: Perineal lacerations could lead to substantial morbidities for women. A reliable prediction model for perineal lacerations has the potential to guide the prevention. Although several prediction models have been developed to estimate the risk of perineal lacerations, especially third- and fourth-degree perineal lacerations, the evidence about the model quality and clinical applicability is scarce. OBJECTIVES: To systematically review and critically appraise the existing prediction models for perineal lacerations. METHODS: Seven databases (PubMed, Embase, The Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, SinoMed, China National Knowledge Infrastructure, and Wanfang Data) were systematically searched from inception to July 2022. Studies that developed prediction models for perineal lacerations or performed external validation of existing models were considered eligible to include in the systematic review. Two reviewers independently conducted data extraction according to the Checklist for critical Appraisal and data extraction for systematic Reviews of prediction Modelling Studies. The risk of bias and the applicability of the included models were assessed with the Prediction Model Risk of Bias Assessment Tool. A narrative synthesis was performed to summarize the characteristics, risk of bias, and performance of existing models. RESULTS: Of 4345 retrieved studies, 14 studies with 22 prediction models for perineal lacerations were included. The included models mainly aimed to estimate the risk of third- and fourth-degree perineal lacerations. The top five predictors used were operative vaginal birth (72.7 %), parity/previous vaginal birth (63.6 %), race/ethnicity (59.1 %), maternal age (50.0 %), and episiotomy (40.1 %). Internal and external validation was performed in 12 (54.5 %) and seven (31.8 %) models, respectively. 13 studies (92.9 %) assessed model discrimination, with the c-index ranging from 0.636 to 0.830. Seven studies (50.0 %) evaluated the model calibration using the Hosmer-Lemeshow test, Brier score, or calibration curve. The results indicated that most of the models had fairly good calibration. All the included models were at higher risk of bias mainly due to unclear or inappropriate methods for handling missing data and continuous predictors, external validation, and model performance evaluation. Six models (27.3 %) showed low concerns about applicability. CONCLUSIONS: The existing models for perineal lacerations were poorly validated and evaluated, among which only two have the potential for clinical use: one for women undergoing vaginal birth after cesarean delivery, and the other one for all women undergoing vaginal birth. Future studies should focus on robust external validation of existing models and the development of novel models for second-degree perineal laceration. PROSPERO REGISTRATION NUMBER: CRD42022349786. TWEETABLE ABSTRACT: The existing models for perineal lacerations during childbirth need external validation and updating. Tools are needed for second-degree perineal laceration.