Incidence and risk factors of third- and fourth-degree perineal tears in a single Italian scenario

Retrospective Case-Control Study of Extended Birth Perineal Tears and Risk Factors

BACKGROUND

A perineal tear is a rupture of the skin or muscle between the vagina and anus (perineum). A third-degree tear is one type of extended perineal tear (EPT), and it involves the penetration of the anal sphincter muscle. Another type of EPT is a fourth-degree laceration, which penetrates deeper into the lining of the anus or rectum. The stretching of the perineum during childbirth may result in perineal trauma. Invasive surgical interventions are required for the treatment of EPTs. For this reason, the reduction of their incidence can be achieved by fully comprehending the risk aspects associated with them.

OBJECTIVE

The aim of this study is to contribute to the body of knowledge by providing insight into the various risk factors that are associated with extended perineal trauma. By following this path, this study aims to contribute to and advance Saudi Arabia's development of evidence-oriented obstetric care recommendations.

STUDY DESIGN

The current study is a case-control study where a review of 5000 vaginal delivery records was carried out between March 1, 2018, and March 19, 2023. For the study, cases (n = 71) were female patients who had documented greater than second-degree perineal injury. The control group (n = 238) was randomly chosen from women who had vaginal delivery but with less or equal to a second-degree perineal laceration. For each patient, we reviewed medical and obstetrics records for the following characteristics: age of diagnosis, gestational age, parity, labor induction, second-stage labor duration, mode of delivery, infant birth weight, epidural use and episiotomy indication, healthcare worker (HCW) experience, and APGAR (appearance, pulse, grimace, activity, and respiration) score.

RESULTS

From the 5000 births analyzed, the cases were 71 patients (1.42% of 5000 births). The mean age at diagnosis in our sample was (28.05 ± 4.66 years). The study's results showed that the following variables significantly affected the occurrence of EPTs: birth weight, labor durations, parity, HCW experience, and mode of delivery. The odds for tears were 3.69 (95% CI: 0.156-0.469) higher in nulliparous patients relative to multiparous patients. Instrumental deliveries resulted in more tears than non-instrumental deliveries with an odds ratio (OR) of 5.901 (95% CI: 2.443-14.525). This study also found that prolonged second-stage labor seems to be associated with an increased risk of perineal damage. HCW experience was looked at in relation to the increased incidence of EPTs, which showed that midwives had a lower incidence rate than physicians with an OR of 2.25 (95% CI: 1.169-4.366). Epidural usage has also been significantly associated with a lesser incidence of perineal tears, which indicates that using epidural could protect against the occurrence of EPTs.

CONCLUSION

In conclusion, the occurrence of perineal lacerations could be prevented during childbirth by taking preventative measures and having more precise judgments. Epidural was a protective factor in our study against the incidence of extensive perineal tearing. Furthermore, as compared to midwives, our study showed that the majority of EPTS occurred in cases of physicians (residents/consultants). Further research, proper documentation, and the development of evidence-based guidelines are needed to improve perineal care and reduce EPT incidence.

Effects of flexible sacrum position at birth on maternal and neonatal outcomes: A retrospective cohort study

OBJECTIVE

To examine the differences in both maternal and neonatal outcomes between flexible and non-flexible sacrum positions at birth.

METHODS

A descriptive, cross-sectional, retrospective study was carried out on a sample of low-risk pregnant women. Univariate and multivariate logistic regressions and multivariate linear regressions were conducted to estimate the association between our discrete or continuous variables of interest. Maternal outcomes were perineal tear, maternal blood loss, second stage length; neonatal outcomes were Apgar scores and neonatal asphyxia. Results were adjusted for maternal age, neonatal birth weight, and epidural analgesia.

RESULTS

We considered for final analysis 2198 women. In primiparous women, women giving birth in the all-fours position were significantly more likely to have an intact perineum (P = 0.011) and a shorter length of the second stage of labor (P = 0.022). Maternal age (P = 0.005) and neonatal weight (P = 0.013) significantly increased perineal tearing; maternal age (P = 0.004) and neonatal birth weight (P < 0.001) were significantly associated with a higher amount of blood loss. Maternal age (P = 0.002) and neonatal weight (P < 0.001) significantly increased the length of the second stage of labor. For multiparous women, the side-lying position was significantly correlated with an intact perineum (P = 0.031); maternal age and intact perineum were statistically inversely associated. Epidural analgesia significantly increased the length of the second stage of labor in both nulliparous (P < 0.001) and pluriparous women (P < 0.001). No significant differences were found in neonatal outcomes.

CONCLUSION

Women with a low-risk labor should be free to choose their birth position as flexible sacrum positions are shown to increase maternal well-being and do not affect neonatal health.

Clinical, ultrasonographic, and functional outcomes after obstetric anal sphincter injury primary repair: A single-center experience

OBJECTIVE

To present clinical and instrumental sequelae after obstetric anal sphincter injuries (OASIS), evaluating correlations between intrapartum severity of lesions, postpartum symptoms, and sonographic and manometric findings; outcomes during subsequent deliveries were also evaluated.

METHODS

This retrospective study evaluated all consecutive women who sustained an OASIS between 2015 and 2020. Postpartum symptoms, anorectal manometry (ARM), and three-dimensional endoanal ultrasonography (3D-EAUS) were analyzed.

RESULTS

A total of 107 women underwent OASIS primary repair; 84 (78.5%) of them were asymptomatic after 1 month. The presence and severity of symptoms showed a great correlation with instrumental outcomes in terms of maximum resting pressure, squeeze pressure increment (SPI), circumferential extension of defect for both external anal sphincter (EAS) and internal anal sphincter (IAS), and EAS, IAS and total Starck scores. There was a significant correlation between ARM and 3D-EAUS findings, with the exception of SPI, for which the abnormalities were not predictable based on EAUS results.

CONCLUSION

Both ARM and EAUS findings after OASIS are directly related to each other, and associated with symptoms. These instrumental tools may be useful for OASIS assessment and counseling.

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.

Neonatal head circumference as a risk factor for obstetric anal sphincter injuries: a systematic review and meta-analysis

OBJECTIVE

Between 53% and 79% of women will sustain some degree of perineal laceration during vaginal delivery. Third- and fourth-degree perineal lacerations are known as obstetric anal sphincter injuries. Timely diagnosis and prompt treatment of obstetric anal sphincter injuries can help to prevent the development of severe consequences like fecal incontinence, urinary incontinence, and rectovaginal fistula. Neonatal head circumference is routinely measured postpartum but is often not mentioned as a risk factor for obstetric anal sphincter injuries in clinical guidelines. Thus far, no review article on the risk factors for obstetric anal sphincter injuries has discussed the role of neonatal head circumference. This study aimed to review and analyze the relationship between head circumference and the occurrence of obstetric anal sphincter injuries among previous studies to conclude whether head circumference should be recognized as an important risk factor.

DATA SOURCES

Through study screening on Google Scholar, PubMed, Scopus, and Science Direct for articles published between 2013 to 2023, followed by assessment of eligibility, this study ended up reviewing 25 studies, 17 of which were included in the meta-analysis.

STUDY ELIGIBILITY CRITERIA

Only studies that reported both the neonatal head circumference and the occurrence of obstetric anal sphincter injuries were included in this review.

METHODS

The included studies were appraised using the Dartmouth Library risk of bias assessment checklist. Qualitative synthesis was based on the study population, findings, adjusted confounding factors, and suggested causative links in each study. Quantitative synthesis was conducted using calculation and pooling of odds ratios and inverse variance using Review Manager 5.4.1.

RESULTS

A statistically significant association between head circumference and obstetric anal sphincter injuries was reported in 21 of 25 studies; 4 studies reported that head circumference was a true independent risk factor. A meta-analysis of the studies that reported neonatal head circumference as a dichotomous categorical variable with a cutoff point of 35±1 cm yielded statistically significant pooled results (odds ratio, 1.92; 95% confidence interval, 1.80-2.04).

CONCLUSION

The risk for obstetric anal sphincter injuries increased as the neonatal head circumference increased-this should be considered in decision-making during labor and postpartum management to attain the best outcome.

Risk factors for obstetric anal sphincter injury recurrence: A systematic review and meta-analysis

BACKGROUND

Women with previous obstetric anal sphincter injuries (OASIs) are at a higher risk of recurrence in the subsequent pregnancy, which may lead to the development or worsening of anal incontinence. Due to a lack of evidence, few recommendations can be made about the factors that may affect the risk of OASI recurrence.

OBJECTIVE

We sought to conduct a systematic review and meta-analysis to investigate potential risk factors for recurrent OASIs.

SEARCH STRATEGY

Studies up to May 2019 were identified from PubMed, Scopus, Cochrane Library, and ISI Web of Science.

SELECTION CRITERIA

Studies assessing the impact of risk factors on OASI recurrence in subsequent pregnancies were included. Reviews, letters to the editor, conference abstracts, book chapters, guidelines, Cochrane reviews, and expert opinions were excluded.

DATA COLLECTION AND ANALYSIS

Data were extracted by two independent reviewers. Odds ratio and standardized mean difference were chosen as effect measures. Pooled estimates were calculated using the random-effects model.

MAIN RESULTS

The meta-analysis showed that maternal age, gestational age, occiput posterior presentation, oxytocin augmentation, operative delivery, and shoulder dystocia were associated with the risk of recurrent OASIs in the subsequent delivery.

CONCLUSION

Prenatal and intrapartum risk factors are associated with recurrence of OASI. PROSPERO registration no. CRD42020178125.

Birth-Related Perineal Tear and Its Associated Factors Among Mothers Who Delivered in Atat Hospital

INTRODUCTION

Birth-related perineal tear or laceration(s) are related to vaginal delivery. Perineal laceration(s) can results in serious maternal morbidity and even mortality in low and middle-income countries, including Ethiopia. The prevalence and determinants of birth-related perineal tear have not been well studied in Ethiopia, particularly in the study area of this research. Therefore, the aims of this research were to determine the prevalence and determinants of birth-related perineal tear among mothers who delivered in Atat Hospital in southern Ethiopia. It was another aim of this study to design an evidence-based intervention and prevention strategies for the reduction of a BPT in the study area and the country based on analysis of data acquired in this research.

METHODS

A hospital-based cross-sectional study was conducted at Atat Hospital from March 1 to August 30, 2021. A total of 422 mothers were included. A systematic random sampling procedure was used to select the study participants. Chart review and interviewer-administered questionnaires were used to collect data. Data entry and analysis were done by using Epi info 7 and SPSS version 20. The strength of associations was assessed by using an adjusted odds ratio with a 95% confidence interval (CI) and statical significance was considered at p-value of less than (<) .05.

RESULT

The prevalence of perineal tears in Atat Hospital was 152 (38.4%) among 396 delivered mothers (95% CI 33.8, 43.4%). Variables found to be related to perineal tear(s) included an episiotomy, (AOR, 2.145,95% CI 1.051, 4.378), fundal pressure (AOR, 7.409, 95% CI 3.157, 17.384), augmentation, (AOR, 4.608,95% CI 2.139, 9.927), and neonatal head circumference (AOR, 3.427,95% CI 2.377, 4.923). These four variables were significantly associated with the perineal tear (p < .05).

CONCLUSION

The prevalence of perineal trauma in this study was high may be be minimized with the use of indicated episiotomy and the lack of fundal pressure. Fundal pressure, augmentation, an episiotomy, and neonatal head circumference were significantly associated factors with the occurrence of perineal tears.

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

BACKGROUND

There is no consensus to the implications of an increased sonographic fetal head circumference (HC) and its impact on delivery.

AIM

To examine if there is any association between sonographic fetal HC, obstetric anal sphincter injury (OASIS) and mode of delivery.

MATERIALS AND METHODS

A retrospective cohort study of term, singleton births between April 2017 and March 2019 at a large regional hospital in Australia with a third trimester ultrasound. Logistic regressions were performed investigating sonographic fetal HC and additional risk factors for OASIS. Further multinomial logistic regressions assessed the relationship between the sonographic HC and mode of delivery. Odds ratios and their 95% CIs were reported.

RESULTS

Of 667 eligible women, 487 (73%) had vaginal births, with 32 (6.6%) sustaining an OASIS and 180 (27%) had caesarean sections (CS). The sonographic fetal HC did not show an association with OASIS (odds ratio 1.005; CI 0.99-1.01, P = 0.447). A statistically significant association (P < 0.05) with OASIS was found with Asian ethnicity (4.38; 1.5-11.32), prolonged second stage (≥2 h) (4.26; 1.57-10.49) and occiput posterior position (4.01; 1.08-11.92). For women with a sonographic fetal HC ≥ 90th percentile, the odds of having CS compared to a spontaneous vaginal birth are 2.77 (95% CI: 1.36, 5.62; P = 0.005) times higher than those who have a HC < 90th percentile.

CONCLUSION

This study does not support the use of sonographic fetal HC in assessing a woman's risk of sustaining an OASIS. Sonographic fetal HC is associated with mode of delivery.

Risk factors associated with severe perineal tears: A five-year study

OBJECTIVE

Our aim was to describe risk factors associated with 34DPT in operative and non-operative vaginal deliveries, over a five-year period.

STUDY DESIGN

This was a retrospective cohort study including 39,227 vaginal deliveries from 2013 to 2017 in a single French University Hospital. Annual characteristics of the analyzed population were recorded. Univariate logistic regression was used to evaluate the association between these characteristics and 34DPT. Multivariate analysis was used to identify combinations of risk factors associated with instrumental delivery.

RESULTS

The rate of perineal tears was constantly rising but rate of 34DPT was stable, ranging between 0.8 and 1.4% over the study period. Cesarean section rate was stable between 18.8% and 19.6%. Rate of diabetes, preeclampsia and obesity (BMI < 40) was increasing and episiotomy rate decreasing (from 19.8% to 11.8%). Operative deliveries rate remained stable between 11 and 12.8%. Multivariate regression showed that gestational age over 39 weeks (aOR 1.18, 95% CI [1.02; 1.35]), birth weight over 3500 g (aOR 1.62, 95% CI [1.05; 2.49]) were associated with 34DPT in patients without operative vaginal deliveries but not episiotomy. Gestational age (aOR 1.71, 95% CI [1.18; 2.47]), episiotomy (aOR 0.55, 95% CI [0.38; 0.79]) and diabetes (aOR 1.73, 95% CI [1.15; 2.61]) were associated with 34DPT among patients with operative vaginal deliveries.

CONCLUSION

In a tertiary medical center model with low cesarean section rate, factors associated with 34DPT were different among patients with or without operative vaginal delivery. The question of the protective effect of mediolateral episiotomy against 34DPT in case of operative delivery deserves further investigations.

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.

A review and comparison of common maternal positions during the second-stage of labor

The second-stage of labor is the most stressful part of childbirth process and the proper maternal position during this period is paramount for women's safe vaginal birth. Midwives play a pivotal role in managing maternal positions during the second-stage of labor. However, there is limited evidence to support an ideal maternal position during the second-stage of labor. Further, the difference between different maternal positions might not be apparent. This paper aims to review and compare the benefits and risks of common maternal positions during the second-stage of labor, thereby to provide midwives evidence-based practical guidelines.

The impact of third- or fourth-degree perineal tears on the second pregnancy: A cohort study of 182,445 Scottish women

This study aimed to investigate the reproductive impact of a third- or fourth-degree tear in primigravid women. A retrospective population-based cohort study was conducted using data from Scottish Morbidity Records (SMR02). Primigravid women with a vaginal birth in Scotland from 1997 until 2010 were included. Exposure was third- or fourth-degree tear in the first pregnancy. The second pregnancy rate, interpregnancy interval and third- or fourth-degree tear in a second pregnancy were the primary outcomes. A nested case-control study was used to determine factors associated with repeat third- or fourth-degree tears in a second vaginal birth. Cox regression analysis and logistic regression were used to look for associations. Initial third- or fourth-degree tear occurred in 2.8% women (5174/182445). The percentage of third- or fourth-degree tears in first vaginal births increased from 1% in 1997 to 4.9% in 2010. There was no difference in having a second pregnancy (adjusted Odds Ratio (aOR) 0.98 (99%CI 0.89–1.09)) or the median interpregnancy interval to second pregnancy (adjusted Hazard Ratio (aHR) 1.01 (99%CI 0.95–1.08)) after an initial third- or fourth-degree tear. Women were over four times more likely to have a repeat injury in a subsequent vaginal birth (n = 149/333, aOR 4.68 (99% 3.52–6.23)) and were significantly more likely to have an elective caesarean section in their second pregnancy (n = 887/3333, 26.6%; 12.75 (11.29–14.40)). Increased maternal age and birthweight ≥4500g were risk factors for repeat injury. Third- and fourth-degree tears are increasing in Scotland. Women do not delay or avoid childbirth after initial third- or fourth-degree tear. However, women are more likely to have a repeat third- or fourth-degree tear or an elective caesarean section in the second pregnancy. Strategies to prevent third- or fourth-degree tears are needed.