Obstetric Anal Sphincter Injuries at Vaginal Delivery: A Review of Recently Published National Guidelines. Obstet Gynecol Surv. 2018;73:695-702. [PMID: 30572346 DOI: 10.1097/ogx.0000000000000622]

Evaluation of French practices in the management and the follow-up of obstetric anal sphincter injuries (OASIS)

OBJECTIVE

The aim was to assess the current management and follow-up of obstetric anal sphincter injuries in maternity wards in France at two levels: the patient's and the care unit level.

STUDY DESIGN

We carried out an evaluation of professional practices in all French maternity hospitals by sending a questionnaire that covered five areas: (i) general information about the hospital, (ii) immediate management of OASIS and postpartum care, (iii) patient follow up, (iv) management of a subsequent pregnancy, and (v) training of health professionals.

RESULTS

During this period, 102 answers (22.4 %) were obtained. Forty-five maternity hospitals (44.1 %) did not have a dedicated protocol for the management and the follow-up of OASIS. In four maternities (4 %), the resident or midwife repaired the anal sphincter alone. Ninety-eight percent of the obstetricians repaired the external anal sphincter using either the end-to-end or overlap techniques. Only two maternities (2 %) used postpartum symptom or quality of life questionnaires after OASIS. In the post-partum, in ten (9.8 %) maternities, patients attended a consultation with an urogynecologist. In this study, 57.8 % patients did not have an anal sphincter ultrasonography prescription in their follow-up even though they had symptoms.

CONCLUSION

We observed a great heterogeneity in the management of patients with OASIS in French maternity hospitals. National guidelines and regular training of health professionals are required to improve this management.

Postnatal Care: A Comparative Review of Guidelines

Importance

Postnatal care refers to the ongoing health care provision of both the mother and her offspring and contributes to the timely identification and effective management of complications in the postpartum period, to secure maternal and infant short- and long-term well-being.

Objective

The aim of this study was to review and compare the most recently published influential guidelines on postnatal care practices.

Evidence Acquisition

A comparative review of guidelines from the American College of Obstetricians and Gynecologists, the World Health Organization, the National Institute for Health and Care Excellence, and the Public Health Agency of Canada regarding postnatal care was conducted.

Results

There is a consensus among the reviewed guidelines regarding the importance of health care provision in the postpartum period, including home visits and midwifery services, the use of telemedicine for the facilitation of communication with the patient, and the appropriate preparation for discharge, as well as the discharge criteria. All medical societies also agree on the clinical aspects that should be evaluated at each postnatal visit, although discrepancies exist with regard to the contact schedule. In addition, there is consistency regarding the management of postpartum infections, perineal pain, fecal and urinary incontinence, and physical activity guidance. Mental health issues should be addressed at each postnatal visit, according to all guidelines, but there is disagreement regarding routine screening for depression. As for the optimal interpregnancy interval, the American College of Obstetricians and Gynecologists recommends avoiding pregnancy for at least 6 months postpartum, whereas the National Institute for Health and Care Excellence recommends a 12-month interval. There is no common pathway regarding the recommended contraceptive methods, the nutrition guidance, and the postpartum management of pregnancy complications. Of note, the World Health Organization alone provides recommendations concerning the prevention of specific infections during the postnatal period.

Conclusions

Postnatal care remains a relatively underserved aspect of maternity care, although the puerperium is a critical period for the establishment of motherhood and the transition to primary care. Thus, the development of consistent international protocols for the optimal care and support of women during the postnatal period seems of insurmountable importance to safely guide clinical practice and subsequently reduce maternal and neonatal morbidity.

Flat Magnetic Stimulation for Urge Urinary Incontinence

Background and Objectives: Strategies for overactive bladder syndrome (OAB) management involve, among others, strengthening the bladder outlet to suppress urgency and neuromodulating the sacral roots. Magnetic stimulation (MS) is a technology that involves an extracorporeal device that is able to provide an electromagnetic field specifically designed to interact with pelvic floor neuromuscular tissue. The resulting tissue electrical activity induces contraction of the pelvic muscle and neuromodulation of the S2-S4 sacral roots. Flat Magnetic Stimulation (FMS) is a relevant advancement involving homogeneous electromagnetic fields, which are able to optimize the effect on the entire pelvic area. However, the benefits of this new technology for OAB syndrome are poorly known. Consequently, the aim of our study is to analyze the outcomes and quality of life (QoL) impact of FMS with Dr. Arnold (DEKA, Calenzano, Italy) in women suffering from OAB syndrome associated with urinary incontinence. Materials and Methods: This prospective study included patients with OAB, urge urinary incontinence, and no ongoing OAB treatments. At baseline (T0), the Incontinence Impact Questionnaire (IIQ-7), the Female Sexual Function Index (FSFI-19), and the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI SF) were collected. Patients underwent 8 FMS sessions of 25 min each in one month. At the termination of the therapy (T1), women repeated the ICIQ-UI SF, FSFI-19, and IIQ-7 tools. Moreover, the Patient Global Impression of Improvement (PGI-I) questionnaire was collected to evaluate the cure rate. Results: Our study enrolled a total of 57 consecutive patients. Most women had at least one second- or third-line treatment before FMS, while the remaining naive patients had contraindications to pharmacological treatments. No women reported adverse effects during the treatment. After the treatment, we observed a decrease in the IIQ-7 (p < 0.001) and ICIQ-UI SF scores (p < 0.001) and an improvement in sexual function (p < 0.001) evaluated with FSFI-19. According to PGI-I scores, 42 (73.7%) women referred to some kind of improvement, scoring ≤ 3 points. Specifically, 8.7% of patients considered themselves very much improved, 29.8% much improved, 35.1% minimally improved, and 26.3% found no changes. FMS was effective in treating OAB symptoms without any adverse effects. The mechanism is supposed to be related to suppressing the initiation of micturition. This makes FMS a promising device for treating naive and refractory urge urinary incontinence. Conclusions: The new FMS represents a promising non-pharmacological option for the treatment of naive and refractory OAB.

Re-evaluation of modifiable risk factors for obstetric anal sphincter injury in a real-world setting

INTRODUCTION AND HYPOTHESIS

The objective was to identify modifiable risk factors for obstetric anal sphincter injury (OASI) in primiparous women.

METHODS

This was a retrospective cohort study of primiparous women with a singleton vaginal delivery. Main outcome measures were incidence of OASI and odds ratios for possible risk factors: maternal age, body mass index and height, fetal birthweight and head circumference, gestational age, epidural analgesia, mediolateral episiotomy, and instrumental deliveries. Univariate and multivariate logistic regressions were performed using forward methods for variable selection.

RESULTS

Of 19,786 primiparous women with a singleton vaginal delivery, 369 sustained an OASI (1.9%). Risk factors were identified: vacuum extraction (adjusted OR 2.06, 95% CI, 1.59-2.65, p < 0.001), increased fetal weight (aOR 1.06, 95% CI, 1.02-1.11, p = 0.002, per 100-g increments); head circumference (aOR 1.24, 95% CI, 1.13-1.35, p < 0.001, per 1-cm increments); gestational week (aOR 1.11, 95% CI, 1.02-1.2, p = 0.012, per week). Protective factors: mediolateral episiotomy (aOR 0.75, 95% CI, 0.59-0.94, p = 0.013) particularly in vacuum deliveries (aOR 0.50, 95% CI, 0.29-0.97, p = 0.040); epidural analgesia (aOR 0.64, 95% CI, 0.48-0.84, p = 0.001); maternal height ≥157 cm (aOR 0.97, 95% CI, 0.96-0.98, p = 0.006, risk decreases by 2.6% per 1 cm increase in height).

CONCLUSIONS

Mediolateral episiotomy was protective against OASI in both spontaneous and instrumental deliveries of primiparae. Increased fetal weight and large fetal head circumference, particularly in short women, were significant risk factors. These findings support the performance of ultrasound to acquire updated fetal measures before admission to the labor ward.

Regional and clinical guidelines for prevention and care of obstetric anal sphincter injuries - A critical frame analysis

OBJECTIVE

Policy documents govern how the prevention and care of obstetric anal sphincter injuries (OASIS) are implemented. Thus, in the absence of Swedish national guidelines on OASIS, differing views may be visible in the regional and local policy documents. Therefore, we aimed to analyse regional and local policies, guidelines, and care programs on the prevention of OASIS and care for OASIS-affected women in a Swedish context by applying a critical frame analysis inspired by Verloo.

DESIGN AND SETTING

A cross-sectional study of existing policy documents from Swedish healthcare regions was performed. The documents were analysed using Verloo's critical frame analysis.

FINDINGS

We found that OASIS was framed as a preventable problem addressed by skilled protective manoeuvres of the healthcare staff. Education, communication, and teamwork were three frames of crucial solutions to minimise the prevalence of OASIS. However, complicating power dimensions between professional groups and between professionals and birthing women were identified. Furthermore, several discursive struggles were found, predominantly regarding the scientific evidence for the suggested prevention and care.

CONCLUSION

The policy documents emphasised that OASIS is preventable, and improved education, communication, and teamwork could diminish the OASIS prevalence. Nevertheless, power dimensions and discursive struggles may challenge the preventive efforts. Furthermore, each Swedish region has the sovereignty to develop its policies, which was reflected in our findings and may imply inequities in care provision. Thus, there is an urgent need to develop comprehensive national high-quality guidelines of high quality for OASIS prevention and care so that all women giving birth have access to equal care and treatment in Sweden.

Antibiotic administration and wound complications after obstetric anal sphincter injuries

BACKGROUND

Obstetric anal sphincter injuries are associated with both short-term and long-term maternal morbidity. Antibiotic administration has been shown to decrease wound complications after obstetric anal sphincter injuries. However, the rate of antibiotic administration in a contemporary obstetrical population is not known.

OBJECTIVE

This study aimed to describe the rate of antibiotic administration for obstetric anal sphincter injuries, to characterize factors associated with antibiotic administration on the day of delivery among women with obstetric anal sphincter injuries, and to determine if there was an association between antibiotic administration and reduced wound complications.

STUDY DESIGN

This was a retrospective cohort study of women with a singleton vaginal birth complicated by obstetric anal sphincter injuries between 2016 and 2021 in a single healthcare system. Information about any antibiotic administration on the day of delivery was collected. Information on wound complications (determined by International Classification of Disease, 10th Revision, codes) that occurred within the first 6 months postpartum were available for patients who delivered at tertiary-care centers. Multivariable logistic regression analysis was used to identify factors associated with antibiotic administration and the association between antibiotics and wound complications.

RESULTS

During the study period, 1550 women met the inclusion criteria of whom 855 (55.2%) received antibiotics. Antibiotic administration was higher at tertiary-care hospitals than at community-based hospitals (68.7 vs 26.8%; P<.001). In the adjusted analysis, antibiotic administration was higher among women with a fourth-degree laceration (adjusted odds ratio, 2.72; 95% confidence interval, 1.69-4.37) and lower among women of Asian or Pacific Islander heritage (adjusted odds ratio, 0.88; 95% confidence interval, 0.80-0.97). At tertiary-care hospitals, 43 women (4.1%) had a wound complication, and more than 80% of those presented within the first 2 weeks postpartum. Antibiotic use was associated with reduced rates of wound complications (adjusted odds ratio, 0.34; 95% confidence interval, 0.13-0.91). All patients received a regimen with gram-positive bacterial coverage; there was no association between type of antibiotic regimen administered and wound complications.

CONCLUSION

Any antibiotic administration on the day of delivery was associated with a decreased rate of wound complications after obstetric anal sphincter injuries. However, only about half of the women with obstetric anal sphincter injuries received antibiotics. Optimizing antibiotic administration may help to reduce the risk of complications in this population.

The association between episiotomy or OASIS at vacuum extraction in nulliparous women and subsequent prelabor cesarean delivery: A nationwide observational study

INTRODUCTION

Severe perineal injuries at childbirth affect women's postnatal health, including future childbirths. First births with vacuum extraction carry an increased risk of obstetric anal sphincter injuries (OASIS). Lateral or mediolateral episiotomy at vacuum extraction may decrease the risk of OASIS. Our aim was to assess whether lateral or mediolateral episiotomy, or OASIS, at vacuum extraction in nulliparous women is associated with prelabor cesarean delivery in the subsequent childbirth.

MATERIAL AND METHODS

This is a nationwide observational study using data from the Swedish Medical Birth Register, including women having a first birth with vacuum extraction and a second birth in 2000-2014. Both births were live, single, cephalic, ≥34 gestational weeks without malformations. The association between episiotomy or OASIS in the first birth and prelabor cesarean delivery in the second birth was examined using univariate and multivariate logistic regression with inverse probability of treatment weighting, and interaction analysis. Main outcome measure was prelabor cesarean delivery in the second birth.

RESULTS

In total, 44 656 women with vacuum extraction at their first birth were included. The rate of prelabor cesarean delivery in the second birth was 5.9% (824 of 13 950) in women with episiotomy, compared with 6.0% (1830 of 30 706) in women without episiotomy. Thus, women with episiotomy did not have an increased risk of prelabor cesarean delivery (adjusted odds ratio [aOR] 1.00, 95% confidence interval [95% CI] 0.83-1.20) compared with women without episiotomy. For comparison, the rate of prelabor cesarean delivery in the second birth was 20.6% (1275 of 6176) in women with OASIS, compared with 3.6% (1379 of 38 480) in women without OASIS (aOR 6.57, 95% CI 5.97-7.23). There was no interaction between episiotomy and OASIS.

CONCLUSIONS

Lateral or mediolateral episiotomy at vacuum extraction in nulliparous women did not increase the risk of prelabor cesarean delivery in the subsequent childbirth. OASIS increased the odds of prelabor cesarean delivery more than sixfold.

Self-assessment of nursing preparedness and knowledge in the care of patients with obstetric anal sphincter injuries and utilization of a computer-based learning module for continued nursing education in the United States

IMPORTANCE

Perineal injury is the most common complication of vaginal delivery, and labor and delivery (L&D) nurses are crucial in managing and educating women following perineal trauma.

OBJECTIVE

The aims of this study were to assess L&D nurse experience, knowledge, and self-perception of preparedness in caring for women with obstetric anal sphincter injuries (OASIS) and to compare pre- and post-test scores using a computer-based learning module (CBL) for OASIS nurse education.

STUDY DESIGN

All L&D nurses were invited to complete a voluntary, self-assessment questionnaire inquiring about prior experience, training, and education and current clinical practice in caring for patients with OASIS. They were also asked to answer ten knowledge-based questions about OASIS. The primary outcome was change in pretest and posttest knowledge-based scores after completion of CBL.

RESULTS

Forty-one L&D nurses voluntarily responded to the self-assessment survey. Of respondents, 20% answered they were "very comfortable", 48% "comfortable", 23% "neutral," and 8% "uncomfortable" for caring for women with OASIS post-delivery. Fifty-three percent of reported having no formal education in nursing school about OASIS and 35% reported no formal training while at work. The average pretest knowledge test score was 66.3% and 93.5% (p < 0.001) after completion of the CBL.

CONCLUSIONS

Most L&D nurses in this study reported having very limited formal nursing education in OASIS. Regardless of this lack of formal training, the majority of L&D nurses in this sample described themselves as comfortable caring for patients with OASIS post-delivery. Completion of a CBL was associated with higher OASIS knowledge scores.

Spontaneous Perineal Trauma during Non-Operative Childbirth—Retrospective Analysis of Perineal Laceration Risk Factors

Childbirth-related perineal trauma (CRPT) is defined as damage to the skin, muscles of the perineum, as well as to the anal sphincter complex and anal epithelium. The aim of the study was to analyze the risk factors for spontaneous injuries to the soft tissues of the birth canal during non-operative delivery. This was a single-center retrospective case-control study. The study included the analysis of two groups, the study group featured 7238 patients with spontaneous perineal laceration (any degree of perineal laceration) and the control group featured patients without perineal laceration with 7879 cases. The analysis of single-factor logistic regression showed that the factors related to perineal laceration during childbirth are the age of the patients giving birth (p = 0.000), the BMI before delivery (p = 0.000), the number of pregnancies (p = 0.000) and deliveries (p = 0.000), diagnosed gestational diabetes (p = 0.046), home birth (p = 0.000), vaginal birth after cesarean (VBAC) (p = 0.001), the use of oxytocin in the second stage of childbirth (p = 0.041), the duration of the second stage of childbirth (p = 0.000), body weight (p = 0.000), and the circumference of the newborn head (p = 0.000). Independent factors that increase the risk of perineal laceration during childbirth are an older age of the woman giving birth, a history of cesarean section, a higher birth weight of the newborn, and factors that reduce the risk of spontaneous perineal trauma are a higher number of deliveries and home birth.

Women's experience and satisfaction with midwife-led maternity care: a cross-sectional survey in China

BACKGROUND

Low risk pregnancy ending in a vaginal birth is best served and guided by a midwife. Utilizing a midwife in such cases offers many emotional and economic advantages and does not increase the risks for mother or neonate. However, women's experience and satisfaction of midwife-led maternity care is rarely reported in China. The primary objective of this study is to describe the experience of Chinese women receiving midwife-led maternity care, and to report their satisfaction level of the experience.

METHODS

The study is a cross-sectional survey of 4192 women who had natural birth from March-June 2019 in a maternity care center, Shanghai, China. We used a self-administered questionnaire addressing items related to women's experience during childbirth, as well as their satisfaction with midwife-led maternity care. We also included demographic and perinatal characteristics of each participant. Descriptive statistics and correlations analysis between groups of different experience and satisfaction were used.

RESULTS

In this sample, 87.7% of women had a Doula and a family member present during childbirth. Epidural anesthesia was used in 75.6% and episiotomy was needed in 23.2%. Free positioning during the first stage of labor and free positioning during the second stage of labor and delivery were adopted in 84.3 and 67.9% of the cases, respectively. Moderate to severe perineal pain and moderate to severe perineal edema were reported in 43.1 and 12.2% of the participants, respectively. High satisfaction level was found when there was midwife-led prenatal counseling and presence of Doula and family member, Lamaze breathing techniques, warm perineal compresses, epidural anesthesia, free positioning during the first stage of labor, and midwifes' postpartum guidance. Negative satisfaction was seen with perineal pain and edema.

CONCLUSION

Women in this survey generally had high satisfaction with midwife-led maternity care. This satisfaction is probably felt because of the prenatal counseling by the midwife and allowing a Doula and a family member in the room during childbirth. Other intangible factors to improve the satisfaction level were Lamaze breathing techniques, warm perineal compresses, epidural anesthesia, free positioning during first stage of labor, and early skin to skin contact.

Observation of the effects of three methods for reducing perineal swelling in children with developmental hip dislocation

BACKGROUND

Developmental dysplasia of the hip is a developmental abnormality of the hip joint that results from hypoplasia during birth and continues to deteriorate after birth.

AIM

To observe the effects of magnesium sulfate wet compress, iodophor wet compress, and ice compress on reducing postoperative perineal swelling in children with developmental hip dislocation to provide effective nursing interventions in the clinic.

METHODS

A total of 120 children with hip dislocation after surgery in a third-class A hospital from January 2018 to January 2020 were randomly divided into four groups, the magnesium sulfate wet compress group, iodophor wet compress group, ice compress group and the control group. Data such as height, weight, age, duration of surgery, intraoperative blood loss, postoperative body temperature, swelling duration, pain score, and incidence of blisters were collected and analyzed.

RESULTS

There were no significant differences in height, weight, age, duration of surgery, intraoperative blood loss, and postoperative body temperature among the four groups of children. Statistical differences were observed between the intervention groups and the control group (P < 0.05).

CONCLUSION

All three methods significantly reduced postoperative perineal swelling in children with developmental hip dislocation, reduced the duration of postoperative perineal swelling, reduced pain, and improved the quality of care.

Management of Breech Presentation: A Comparison of Four National Evidence-Based Guidelines

OBJECTIVE

The management of breech presentation may improve perinatal outcomes. The aim of this study was to synthesize and compare published evidence of four national guidelines on breech presentation.

STUDY DESIGN

A descriptive review of four recently published national guidelines on breech presentation and external cephalic version (ECV) was conducted: Royal College of Obstetricians and Gynaecologists guideline on "External Cephalic Version and Reducing the Incidence of Term Breech Presentation" and "Management of Breech Presentation", American College of Obstetricians and Gynecologists guideline on "External Cephalic Version" and "Mode of Term Singleton Breech Delivery," Society of Obstetricians and Gynaecologists of Canada guideline on "Vaginal Delivery of Breech Presentation" and the Royal Australian and New Zealand College of Obstetricians and Gynaecologists guideline on "Management of breech presentation at term."

RESULTS

Regarding ECV, there is no recommendation by the SOGC, whereas all other national guidelines recommend this technique. Regarding breech vaginal delivery, there are limited recommendations by the ACOG, whereas all other guidelines provide similar recommendations. The RANZCOG makes no special recommendations on the intrapartum period.

CONCLUSION

The differences among national guidelines point out the need for the adoption of an international consensus on the management of breech presentation.

Review of available national guidelines for obstetric anal sphincter injury

INTRODUCTION AND HYPOTHESIS

Obstetric anal sphincter injuries (OASIs) are the most severe form of perineal trauma with potentially devastating effects on a mother's quality of life. There are various national guidelines available for their management. The aim of this study was to review and compare recommendations from published national guidelines regarding management and prevention of OASI.

METHODS

We searched the PUBMED, EMBASE, MEDLINE, CINAHL and COCHRANE databases from January 2008 till October 2019 using relevant Medical Subject Headings (MeSH), including all subheadings. The guideline characteristics were mapped and methodological quality assessed with the Appraisal of Guidelines for Research and Evaluation (AGREE) II tool by three independent reviewers. To compare the methodological quality of the guidelines, the interpretation of the six domain scores were taken into consideration. By consensus of the authors, a score of 70% was taken as a cut-off, and scores above this were considered 'high quality'.

RESULTS

Thirteen national guidelines on perineal trauma were included and analysed. Nine of these were specific to OASI. There is wide variation in methodological quality and evidence used for recommendations. AGREE scores for overall guideline assessment were > 70% in eight of the guidelines, with Australia-Queensland, Canada, the UK and USA scoring highest.

CONCLUSIONS

The wide variation in methodological quality and evidence used for recommendations suggests that there is a need for an agreed international guideline. This will enable healthcare practitioners to follow the same recommendations, with the most recent evidence, and provide evidence-based care to all women globally.

SMFM Special Statement: Operative vaginal delivery: checklists for performance and documentation

The frequency of operative vaginal delivery has been declining, even though it can be an attractive alternative to cesarean delivery in selected cases. Performance of operative vaginal delivery required consideration of many indications, contraindications, and prerequisites. Optimal documentation of operative vaginal delivery requires the recording of several specific elements that are unique to forceps or vacuum delivery. A cognitive aid such as a checklist is well suited to this situation in which there are numerous elements to consider, a low frequency of performance, and teams with variable expertise. We propose 2 checklists to help ensure that all relevant elements are considered for every operative vaginal delivery: (1) a checklist for preparation and performance of the procedure and (2) a checklist for documentation. We suggest practical tips to help facilities adapt these checklists to their own circumstances and implement them on their units.

Operative vaginal delivery: a review of four national guidelines

There is a broad range in the rates of operative vaginal deliveries (OVD) worldwide, which reflects the variety of local practice patterns, the number of trained clinicians and the lack of international evidence-based guidelines. The aim of this study was to review and compare the recommendations from published guidelines on OVD. Thus, a descriptive review of guidelines from the Royal College of Obstetricians and Gynaecologists (RCOG), the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG), the Society of Obstetricians and Gynaecologists of Canada (SOGC) and the American College of Obstetricians and Gynecologists (ACOG) on instrumental vaginal birth was conducted. All the guidelines point out that the use of any instrument should be based on the clinical circumstances and the experience of the operator. The indications, the contraindications, the prerequisites and the classification for OVD are overall very similar in the reviewed guidelines. Further, they all agree that episiotomy should not be performed routinely. The RCOG, the RANZCOG and the SOGC describe some interventions which may promote spontaneous vaginal birth and therefore reduce the need for OVD. They also highlight the importance of adequate postnatal care and counseling. There is no consensus on the actual technique that should be used, including the type of forceps or vacuum cup, the force and duration of traction or the number of detachments allowed. Hence, there is need for international practice protocols, so as to encourage the clinicians to use OVD when indicated, minimize the complications and reduce rates of cesarean delivery.

Risk factors for severe perineal trauma during childbirth: An updated meta-analysis

Several studies have investigated the importance of maternal, fetal factors and intrapartum characteristics in predicting severe perineal lacerations. The purpose of the present systematic review is to accumulate current evidence and provide estimated effect sizes for the various risk factors described. We reviewed Medline, Scopus, Clinicaltrials.gov, EMBASE, Cochrane Central Register of Controlled Trials CENTRAL and Google Scholar for published studies in the field for observational studies as well as randomized controlled trials. Two researchers independently assessed the included studies and documented outcomes. Data extraction was performed using a modified data form that was based in Cochrane`s data collection form for intervention reviews for RCTs and non-RCTs. Forty-three articles were selected for inclusion in the present systematic review. The analyzed population reached 716,031 parturient of whom 22,280 (3,1%) sustained third- and fourth-degree perineal lacerations. Several risk factors were identified. Instrumental delivery [RR 3.38 (2.21, 5.18)], midline episiotomy [RR 2.88 (1.79, 4.65)] and a persistent occiput posterior position [RR 2.73 (2.08, 3.58)] were associated with the higher risk of developing severe perineal lacerations. Mediolateral episiotomy did not increase, but was also not protective against perineal lacerations [RR 1.55 (0.95, 2.53)]. Several factors contribute to the development of severe perineal lacerations. The present meta-analysis presents accumulated data that may help physicians estimate risks and provide appropriate patient counseling.