Research Article

Association of Anal Sphincter Tears with The Quality of Life in Women. The Prognostic Factors

Nikoleta Tsinisizeli^1,2*, Anna Deltsidou¹, Aikaterini Lykeridou¹, Anastasia Bothou¹ and Giannoula Kyrkou¹

¹Midwifery Department, University of West Attica

²General Hospital of Nikaia “Agios Panteleimon”

Submission: September 13, 2024;Published: September 23, 2024

*Corresponding author: Nikoleta Tsinisizeli, Midwifery Department, University of West Attica, Greece, Email: nikoletatsinisizeli@gmail.com

How to cite this article: Νikoleta Tsinisizeli, Anna Deltsidou, Aikaterini Lykeridou, Anastasia Bothou and Giannoula Kyrkou. Association of Anal Sphincter Tears with The Quality of Life in Women. The Prognostic Factors. J Gynecol Women’s Health 2024: 27(1): 556202. DOI: 10.19080/JGWH.2024.27.556202

Abstract

Introduction: Perineal injuries affect hundreds of thousands of women in Europe and millions worldwide every year. Vaginal births are associated with causing some form of trauma to the genital system.

Aim: The aim of this literature review is to investigate and inform the readers about the current literature on the subject of the prognostic factors blamed for causing vaginal and perineal ruptures and to correlate them with the impact on the woman’s quality of life.

Methodology: The present literature review was based on the PRISMA method (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), and aggregated data published in international literature. The electronic databases used were PubMed, Scopus and Google Scholar.

Results: The search identified 123 articles. The titles and abstracts of the articles were re-evaluated and those that were not related to the subject were excluded.

Conclusion: The prediction of risk factors should precede the obstetric practice. Both early intervention and effective treatment constitute the best practice. Weighing the benefits and risks of providing proper counseling to women of childbearing age by obstetricians and midwives should be a key goal of specialists in the prevention of severe perineal trauma.

Keywords: Perineal, Obstetric Injuries, Quality of life and Risk factors

Abbreviations: ACOG: American College of Obstetricians and Gynecologists; OASIS: Obstetric Anal Sphincter Injuries

Introduction

Morbidity related to perineal trauma is an international issue. Perineal injuries affect hundreds of thousands of women in Eu­rope and millions worldwide every year. Vaginal births are associ­ated with causing some form of trauma to the genital system. It is estimated that vaginal tears occur in 85% of primiparous women who give birth by spontaneous vaginal delivery [1]. The anterior perineal wound can be located on the lips of the vulva, in the area of the urethra, clitoris and anterior area of the vagina and usual­ly is associated with low morbidity. Posterior perineal trauma is found in the posterior area of the vagina, the muscles and body of the perineum and the sphincter anus [2]. Injury to the perineum is common in vaginal delivery. It occurs in 65-85% of vaginal deliv­eries with a higher incidence in primiparous women (90.8%) compared to multiparous women (68.8%) [3]. However, almost 20% of 3^rd and 4^th degree tears are not diagnosed and are not repaired during the postpartum period which is associated with long-term consequences in the life of the woman [4]. The soft tissues of the genital tract during childbirth are injured either by spontaneous ruptures or by induced ruptures by performing an episiotomy [5].

The extent of the tear to the sphincter and then to the rectal mucosa determines the severity of the tear. Obstetric injuries are classified from first to fourth degree and this is determined by the anatomical structures involved in this tissue damage. A classifica­tion system for obstetric perineal injuries has been proposed ini­tially by Sultan and later by the American College of Obstetricians and Gynecologists (ACOG) [6]. First degree tears include damage to the perineal skin and vaginal epithelium without the fascia and muscles and occur in 50% of cases. In these cases, healing is immediate, while suturing may not be required in minimal situ­ations. Second-degree tears involve the skin and muscles of the perineum, excluding the anal sphincter. Third- and fourth degree tears involve the anal sphincter and anal mucosa respectively and are referred to the literature as OASIS (Obstetric Anal Sphincter Injuries) [7].

Severe perineal trauma, including third-or fourth degree rup­ture contributes to maternal morbidity and is associated with short term unpleasant conditions such as infection, rupture and long term chronic perineal pain, urinary problems, fecal inconti­nence and sexual dysfunction accompanied by severe dyspareunia [8,9]. Third-and fourth degree perineal tears range from 5.1% to 8.3% in primiparous women [10]. Primiparous women who expe­rience severe perineal trauma has been found to be at significant risk of developing post-traumatic stress disorder [1]. In particular, a severe perineal trauma may lead to significant and irreversible consequences both in the care of the infant and in woman’s social and sexual life. As a result, these women refuse to plan or accept a new pregnancy [11].

Approximately 50% of women of reproductive age report anal incontinence after anal sphincter injury affecting the woman’s quality of life. Pelvic dysfunctions as a result of obstetric perine­al injuries are the main cause of embarrassment, low self-esteem, depression and social isolation of a woman [9]. Severe perineal tears increase a country’s overall health care costs significantly. In the United States the cost during the ages 2007 to 2011 amounted to 83 million dollars [12]. In the United States of America 3 mil­lion women will give birth vaginally every year and 4.4% of them will experience a third- or fourth-degree rupture [13]. Annual­ly, during the years 2000 to 2010 in the United Kingdom 30,000 women presented 3^rd or 4^th degree perineal trauma. This situation increased the healthcare costs at $31,000,000 [14]. Particular at­tention should be given to the identification of prognostic risks and especially to the mitigation of modifiable risk factors in order to reduce the incidence of obstetric trauma and the subsequent comorbidity.

Risk Factors

Numerous studies have evaluated a variety of prognostic fac­tors, fetal and maternal, modifiable and nonmodifiable, as well as iatrogenic manipulations that may lead to the occurrence of se­vere perineal injuries. Specifically, Asian ethnicity [15], primipar­ity, obesity [7], vulvo and anal distance less than 4cm and mater­nal age older than 35 years due to changes in connective tissue elasticity and weakness of the pelvic floor muscles are the main maternal factors [5,16,17]. In particular, according to the World Health Organization, a BMI ranging from 25 to 29 is defined as overweight, while in obesity the BMI is greater than 30 [18]. Also, according to studies, women of Africa have four times the risk of anal sphincter rupture compared to women of different ethnicity [11]. Abnormal positions, newborn’s weight greater than 4000g or fetal macrosomia and the head circumference of the newborn are fetal risk factors [1,10,17,19].

Risk factors such as vaginal delivery, the use of forceps or vacu­um extraction, prolonged second stage of labor, shoulder dystocia, misjudgment of episiotomy, vaginal delivery after caesarean sec­tion with a risk rate of 21% (VBAC), median episiotomy [12,17], exogenous oxytocin administration, spontaneous versus directed pushing [20] as well as epidural analgesia constitute the iatrogen­ic risk factors [2,12,17,21,22]. The timing of pushing during the second stage of labour is under discussion. In early pushing the women accept instructions to push when the cervix is fully dilated while in the case of delayed pushing, the women push when the fetal head projects to the perineum, extending the second stage of labor by approximately one hour [20].

However, great importance should be given to the position of the woman during labour avoiding the lithotomy position with an emphasis on the education of the woman. The rotation of po­sitions during the first and second stage of labor influences the risk factors positively or negatively. Upright and lateral positions during the second stage of labour increase the pelvic diameters in contrast to the supine position which increases the possibility of operative vaginal delivery [12]. Studies have shown that regard­less of whether an episiotomy is performed, the use of forceps or vacuum increases the chances of severe perineal trauma [23]. Perineal edema is an independent risk factor for anal sphincter rupture. Specifically, for every ten minutes that the second stage of labor is prolonged, the risk of causing a severe perineal tear in­creases by 6% and this is likely due to perineal edema [24]. The purpose of this literature review is to investigate the prognostic factors blamed for causing vaginal and perineal ruptures and to correlate them with the impact on the woman’s quality of life.

Methodology

The aim is to inform readers about the current literature on the subject of prognostic factors in the occurrence of perineal trauma. The present literature review was based on the PRISMA method (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), and aggregated data published in international literature. The research questions were identified, the purpose and objective of the present bibliographic review were defined, the literature was searched, the results were extracted and pre­sented. The electronic databases used were PubMed, Scopus and Google Scholar. The search was limited to articles published from 2019 to identify recent studies relevant to the review question and predictors associated with the occurrence of childbirth-re­lated perineal trauma. Key words and phrases were used such as perineal, obstetric injuries, quality of life and risk factors. Only studies in which the publication was in English were included. Ab­stracts and conference papers were excluded. Article titles and ab­stracts were re-evaluated if their content deviated from our main research question (Figure 1).

Results

During our systematic review process and limiting our re­search to the last five years the search identified 123 articles. The titles and abstracts of the articles were re-evaluated and those that were not related to the subject were excluded. Duplicate articles were removed, and results were limited to 24 articles. Completing the systematic review and the analysis of 24 articles, the main risk factors are summarized in (Table 1). These include neonatal birth weight (13 papers), episiotomy (especially midline episiotomy in comparison with mediolateral episiotomy) (13 papers), prim­iparity (9 papers), occipito posterior (9 papers), maternal age > 30 years (7 papers), oxytocin administration (8 papers), shoulder dystocia (6 papers), Asian ethnicity (6 papers), body mass index (3 papers), gestational age (2 papers), epidural (2 papers), amni­otomy (1 paper), hands on technique (1 paper), upright positions (1 paper) and head circumference (1 paper). Last but not least, the most common aggravating factor is instrumental delivery es­pecially forceps and vacuum extraction delivery (16 papers).Zang et al reported that upright positions constitute a modifiable risk factor.

Nevertheless, the remaining studies do not confirm the above finding. Barbieri et al reported epidural anesthesia as a risk factor for severe perineal tear. As before, the remaining 23 studies do not report epidural anesthesia as a risk factor. Constable et al, Sartore et al and Peiris - John et al, report body mass index of women <25 as a risk factor while higher BMI is referred to be protective for perineal trauma. Factors associated with an increased risk for 3^rd and 4^th degree rupture were vacuum extraction and forceps assist­ed delivery. According to 9 articles (Table 1), the above risk fac­tor acts more aggravatingly in primiparous women. The weight of the newborn is reported as an increased risk factor for the occur­rence of perineal tear. Most studies refer to a weight greater than 4.000gr and others to a weight greater than 3.600gr. Peiris-John et al refer to the type of episiotomy which seems to influence the ef­fect of labour. According to 13 studies midline episiotomy is a sig­nificant risk factor for obstetric anal sphincter injury. On the other hand, it seems that mediolateral episiotomy has a protective effect especially of a combined use of forceps or vacuum extraction de­livery. Klokk et al, refer to the risk factor of instrumental delivery in primiparous women as well as to amniotomy as a modifiable risk factor. It is worth noting that most risk factors are not inde­pendent factors but require the combination of two or more ag­gravating factors.

Discussion

Meta-analysis of 24 studies showed that risk factors presented in (Figure 2) are associated with OASIs risk. Confounding factors such as ethnicity, different obstetric practices, newborn weight, maternal characteristics could affect the results. A major draw­back in the failure to reduce the rates of anal sphincter tears is the existence of non-modifiable risk factors such as the woman’s age, primiparity, ethnicity, vulva-anal distance, head circumference of the neonate, and its physical weight [25].

In a systematic review of 25 studies by Raihan et al, it was found that a head circumference greater than 35 cm is an inde­pendent risk factor for the occurrence of a severe perineal tear [10]. Nevertheless, the non-modifiable factors could be the start­ing point for avoiding some aggravating manipulations during de­livery. According to a study by Sartore et al on 266 primiparous women who gave birth by spontaneous vaginal delivery in a hos­pital in Trieste in Italy during the years 2015-2022 was found that the incidence of perineal tears ranged from 53% to 85%. In cases of severe perineal tears 3^rd - 4^th grade, pelvic disorders persisted or even worsened over time [1]. Globally, the prevalence rates of perineal tears 3^rd and 4^th grade vary from country to country. For example, in countries with low-income criteria such as the Phil­ippines, the incidence rate of perineal trauma is 15%, while the lowest rate of 0.1% occurs in Cambodia. In developed countries such as Canada, the percentage is 3.1%.

Because of these discrepancies, obstetric practice varies from country to country as well as the management of major trauma [26]. Klokk et al performed a clinical study in a maternity hospital in south-eastern Norway on modifiable and non-modifiable risk factors, for the occurrence of severe perineal tear and found that the risk of OASIS was associated with primiparity, maternal age, neonatal birth weight, induction of labor and use of suction or metallic forceps. A strong independent factor was found to be the rupture of fetal membranes [27].

In a study by Zang et al, it was found that upright positions during childbirth work positively in preventing the occurrence of 3^rd and 4^th degree obstetric trauma [28]. A systematic review by Packet et al found that the most important risk factors for severe perineal trauma were shoulder dystocia and operative vaginal de­livery [17]. Orlando et al regarding operative vaginal delivery as a risk factor for anal sphincter ruptures found that not only the use of metal forceps but also the use of suction were associated with a risk rate of 12% and 7% for severe perineal ruptures, respectively [29]. In the review of Orlando et al, were assessed confounding factors such as ethnicity and episiotomy. The risk of severe peri­neal tears was more associated with primiparous women at 5% in comparison with multiparous women at 2.5% in case of mediolat­eral episiotomy [29].

Regarding obesity, the results are controversial. In Australia, a retrospective study by Constable et al comparing the incidence of OASIS with women’s BMI found that women with a BMI >25 were more likely to have 3^rd-4^th degree perineal tears compared to women with BMI<25. A possible protective effect appears to be the greater distance between the anal sphincter and the vagina in overweight women as well as greater distension of the perineum due to increased adipose tissue [18].

The study of Joris et al supports the protective effect of high BMI on the pelvic floor during labor. This is likely due to the fact that obese women have higher levels of cholesterol which reg­ulates the effectiveness of the oxytocin receptor in the smooth muscles of the uterus [30]. The above study contradicts the study of Darmody et al which supports obesity as a risk factor for the occurrence of severe perineal tears [7]. Hu et al in a systematic review found that a prior caesarean section is a risk factor for 3^rd and 4^th degree perineal tears in a subsequent vaginal delivery. It is important that there are studies evaluating the risk of obstet­ric trauma during vaginal delivery after caesarean section since more and more women feel the desire to live the experience of natural childbirth even after caesarean section [31]. However, the existence of possible confounding factors such as gestational diabetes mellitus, macrosomia, prolonged second stage of labor, operative vaginal delivery and ethnicity must also be taken into account. High rates of operative vaginal delivery as a measure to reduce caesarean section rates could lead to an increase in the in­cidence of severe perineal injury [32]. The World Health Organi­zation estimates that 99% of maternal morbidity and mortality is observed in low-income countries, possibly due to malnutrition, poor hygiene conditions and insufficient sterilization of materials or antisepsis of the perineal area during suturing [33].

In a study by Chill et al it was found that a previous operative vaginal delivery and a difference greater than 500 grams in the body weight of the newborn in relation to the previous delivery are two strong independent risk factors for the occurrence of a se­vere anal sphincter tear [25]. This could possibly be explained due to a change in the normal structure of the pelvis following a pos­sible injury to the connective tissue and muscles of the perineum. The use of metal forceps along the fetal head is associated with a greater risk of 3^rd and 4^th degree perineal tears because of the in­crease to the transverse diameter increasing the perineal pressure [34]. However, the likelihood of perineal injury is influenced not only by fetal or maternal factors but also by the experience and skills of the person performing the delivery. A systematic review by Wilson et al found that prenatal perineal massage around 35 weeks of pregnancy in primiparous women reduced the incidence of perineal trauma and the need for episiotomy by 16% [23].

Selective use of episiotomy according to studies can reduce the incidence of 3^rd and 4^th degree perineal tears by 30% to 50% [23,35]. In case of midline episiotomy there is an increased risk of extension of the tear into the anal sphincter [34]. The system­atic review by Aguiar et al collected data from 300,000 vaginal births to estimate the incidence of 2nd, 3^rd and 4^th degree ruptures in relation to episiotomy’s frequency. It was found that in 46% of vaginal deliveries an episiotomy was performed, 23% had a 2nd de­gree tear while 1.4% had a 3^rd and 4^th degree tear [33]. Although in most studies the performance of mediolateral episiotomy exerts a protective effect in causing a severe perineal tear, the review by Pergialiotis et al does not confirm the above result [36]. According to Ramphal et al, slowing the delivery of the fetal head through directed pushing and proper guidance of the woman to avoid pre­mature expulsion would reduce the rate of anal sphincter rupture by 50-70% [37].

In a review of 13 studies and a total number of 3338 women, it was found that delivery using vacuum or metal forceps was as­sociated with an increased risk of rupture of the anal sphincter regardless of whether or not an episiotomy was performed. In particular, this risk was more increased with the use of the met­al forceps [38]. The systematic review by Barba et al concluded that 2.3 cesarean sections are sufficient to avoid a case of anal in­continence owing to a severe perineal tear implying an increased chance of choosing a cesarean section at the next birth [39]. The two effective steps to improve the quality of life of the woman in addition to prevention are the determination of the degree of per­ineal tear and the immediate repair during labor [15]. Particular importance should be given to the examination of the perineum following the repair of the perineal tear or episiotomy, because there is a risk of intestinal mucosa injury and formation of a rec­tal fistula. The correct triad for perineal tears includes prevention, recognition and repair [26].

Findings identified that women who experienced trauma to the anal sphincter felt ashamed, hid the condition they were expe­riencing, felt undignified, less attractive and ready to accept their new body image [7]. These women present a huge gap between their expectations of birth experience and reality. This influenc­es not only the relationship with their husbands\partners but also with their babies [23]. Midwives’ awareness of the correct assessment of obstetric trauma is imposed. The prevention of se­vere ruptures should be a goal for every midwife and obstetrician, while their continuing professional education in the diagnosis and repair of anal sphincter tears should be encouraged. Planned ce­sarean delivery is not a measure of primary prevention of obstet­ric injuries and protection of the perineum (Ducarme et al 2019), [23].

Conclusion

The early recognition of the risk factors in order to minimize them, the early diagnosis of the perineal injury and its treatment by the right scientific team would have an extremely positive effect on the woman’s quality of life. Particular importance must be giv­en to the training of midwives and gynecologists in the anatomy of the pelvis and especially the perineum, with an emphasis on tears in the perineal area. Correct and early diagnosis of perineal tears appears to improve the postpartum period of the woman [23]. However, prediction of risk factors should precede the obstetric practice. Both early intervention and effective treatment consti­tute the best practice. Weighing the benefits and risks of providing proper counseling to women of childbearing age by obstetricians and midwives should be a key goal of specialists in the prevention of severe perineal trauma and pelvic disorders [40,41]. The expe­rience of childbirth is important for women and the quality of this experience affects the relationship between mother and child. The assessment of their expectations needs and experiences during la­bour is essential. As a result, this preventive care would minimize the complications and would improve the self-esteem and wom­en’s quality of life.

Funding

Open access funded by the Special Account for Research Grants of the University of West Attica.

Conflicts of Interest

The authors declare no conflicts of interest regarding the pub­lication of this paper.

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