INTRODUCTION — Episiotomy is performed to enlarge the birth outlet and facilitate delivery of the fetus. Routine use of episiotomy has fallen out of favor based on evidence of increased complications with use. Episiotomy is now performed on an individualized basis. Episiotomy is considered when the clinical circumstances place the patient at high risk of a third or fourth degree laceration or when the fetal heart tracing is of concern and hastening vaginal delivery is warranted. Mediolateral episiotomy is associated with a lower risk of third and fourth degree laceration than a median episiotomy.
This topic will review the indications, risks, benefits, and procedure for episiotomy. The repair of episiotomy and obstetric anal sphincter laceration are presented separately.
DEFINITION — Episiotomy is the surgical enlargement of the posterior aspect of the vagina by an incision to the perineum during the last part of the second stage of labor . The incision is performed with scissors or scalpel and is typically midline (median) or mediolateral in location. (See 'Procedures and selection' below.)
PREVALENCE AND RISK FACTORS — Since the 1996 World Health Organization recommendation for an episiotomy rate of approximately 10 percent , rates of episiotomy have generally been in decline. In the United States, the episiotomy rate dropped from 17.3 to 11.6 percent from 2006 to 2012 . In Canada, episiotomy rates dropped for both operative and spontaneous vaginal deliveries between 2004 and 2017 (operative vaginal deliveries from 53 to 43 percent and spontaneous vaginal deliveries from 13.5 to 6.5 percent, respectively) .
In a study from a United States insurance database, episiotomy was more common in White women and those with commercial insurance . Hospital factors including rural location or academic center were associated with reduced rates of episiotomy. Other studies have reported that private practitioners have two- to fourfold increased utilization of episiotomies compared with trainees, academic faculty, or midwives [3,5,6].
LACK OF ADVANTAGES FOR EPISIOTOMY USE — Routine use of episiotomy is no longer recommended because of insufficient objective evidence-based data demonstrating benefit or defining the criterion for its use [7-9]. In addition, restricted use of episiotomy decreases the risk of severe (ie, third and fourth degree) obstetric lacerations. In a meta-analysis of 12 trials comparing restrictive episiotomy use with routine use in women expecting an unassisted vaginal birth, restrictive episiotomy resulted in up to 30 percent fewer women sustaining severe perineal or vaginal trauma (risk ratio [RR] 0.70, 95% CI 0.52-0.94, 5375 women, eight trials) . There were no differences between the groups in postpartum day 3 perineal pain, long-term (six months or more) dyspareunia, urinary incontinence, or genital prolapse.
In the past, routine use of episiotomy was believed to have several benefits; however, the body of evidence does not support these beliefs :
●Reduction of trauma to the fetal head – Although episiotomy has been advocated to minimize the risk of intraventricular hemorrhage in preterm births, there is no evidence that this intervention is effective on a routine basis . (See "Long-term neurodevelopmental outcome of preterm infants: Epidemiology and risk factors".)
●Ease of repair and improved wound healing – It has been historically argued that a controlled surgical incision is easier to repair and more likely to be anatomically correct than repair of a spontaneous laceration, and thus less likely to result in long-term complications. In the absence of episiotomy extension, episiotomy incision is easier to repair than most jagged spontaneous deep second degree lacerations. However, data demonstrating improved long-term outcomes with episiotomy are lacking. (See "Repair of perineal and other lacerations associated with childbirth".)
●Preservation of the muscular and fascial support of the pelvic floor – Episiotomy also does not protect pelvic floor strength and may result in a weakened pelvic floor musculature when compared with spontaneous laceration [12-16]. In addition, neither midline nor mediolateral episiotomies are protective against future urinary or fecal incontinence when compared with spontaneous vaginal delivery [12,17].
●Prevention of anal sphincter laceration – There is increasing consensus that the median episiotomy is not effective for this purpose and, in fact, has been associated with an increased rate of severe perineal lacerations. In a meta-analysis of 22 observational studies that included over 651,000 women (2.4 percent with severe lacerations), median episiotomy was associated with a nearly fourfold increased risk of third- or fourth-degree perineal lacerations (odd ratio [OR] 3.82, 95% CI 1.96-7.42) . Of note, mediolateral episiotomy did not increase the risk of severe perineal laceration (OR 1.72, 95% CI 0.81-3.65). In a subsequent meta-analysis with 43 studies and 716,000 women (3.1 percent with severe lacerations), median episiotomy was again associated with an increased risk (RR 2.88 [1.79, 4.65]) . Mediolateral episiotomy was not protective but also not associated with an increased risk (RR 1.55 [0.95, 2.53]). (See "Fecal and anal incontinence associated with pregnancy and childbirth: Counseling, evaluation, and management", section on 'Role of obstetric factors' and "Obstetric anal sphincter injury (OASIS)", section on 'Epidemiology and risk factors'.)
●Prevention of shoulder dystocia – In a systematic review of 14 studies including over 9700 cases of shoulder dystocia, only one study evaluated the effect of episiotomy on prevention of shoulder dystocia, and the result was not significant . While episiotomy does not appear to prevent shoulder dystocia, its use in the management of shoulder dystocia is less clear. (See 'When to consider episiotomy' below.)
ADVERSE OUTCOMES OF EPISIOTOMY — When considering the use of episiotomy, the clinician balances the potential benefits of episiotomy against potential adverse effects resulting from this procedure, including:
●Extension of the incision, leading to third- and fourth-degree tears, particularly for median episiotomy [18,19,21].
●Risk of unsatisfactory anatomic results (eg, skin tags, asymmetry, fistula, narrowing of introitus).
●Increased blood loss .
●Higher rates of infection and dehiscence .
●Increased risk of severe perineal laceration in subsequent deliveries .
WHEN TO CONSIDER EPISIOTOMY — The decision to perform episiotomy is heavily dependent on the opinion of the delivering clinician and is based on the clinical scenario at the time of delivery [10,24]. There are no specific situations in which episiotomy is essential. It is a reasonable option when the clinician believes enlarging the birth outlet to facilitate delivery of the fetus will benefit the mother or baby and warrants maternal exposure to the potential adverse outcomes associated with the procedure. For example:
●Expedite delivery of the fetus – Episiotomy can be helpful in situations where expedited delivery of the fetus is desired during the second stage of labor, such as with a category III fetal heart rate tracing that does not respond to resuscitative measures. Episiotomy is only helpful if delivery is being blocked by perineal tissue (ie, episiotomy will not improve maternal expulsive efforts). (See "Intrapartum category I, II, and III fetal heart rate tracings: Management", section on 'Category III pattern'.)
●Operative vaginal delivery – Episiotomy can be used to facilitate placement of the forceps or vacuum extractor in women with a narrow vaginal outlet. In contrast to historical recommendations, multiple societies advise against routine episiotomy with operative vaginal delivery; the decision to perform an episiotomy during an operative vaginal delivery is at the discretion of the clinician [24-29]. As median episiotomy during an operative vaginal delivery triples the risk of an anal sphincter injury compared with operative vaginal delivery alone, median episiotomy is not advised [30,31].
When episiotomy is performed, mediolateral episiotomy is associated with a lower risk of anal sphincter injury compared with median episiotomy [18,21]. In a systematic review and meta-analysis of 15 studies comparing mediolateral or lateral episiotomy with no episiotomy in primiparous women undergoing vacuum assisted delivery, mediolateral or lateral episiotomy was associated with an approximately 50 percent reduction in risk of anal sphincter laceration compared with no episiotomy (odds ratio 0.53, 95% CI 0.37-0.77) . Based on this study, 19 women would have to undergo mediolateral or lateral episiotomy during vacuum extraction to prevent one anal sphincter laceration. For clinicians who elect to perform an episiotomy to facilitate delivery, we advise a mediolateral or lateral incision. We evaluate all nulliparous women undergoing operative vaginal delivery for possible episiotomy and are likely to perform a mediolateral or lateral episiotomy in women with a short perineum.
Of note, operative vaginal delivery is an independent risk factor for advanced perineal laceration [18,19]. (See "Fecal and anal incontinence associated with pregnancy and childbirth: Counseling, evaluation, and management", section on 'Role of obstetric factors'.)
●Shoulder dystocia – In some cases of shoulder dystocia, performing an episiotomy can increase space for the operator's fingers and thus facilitate delivery of the posterior shoulder and other internal procedures, but does not appear to prevent shoulder dystocia or release the impacted anterior shoulder. Routine use of episiotomy to manage shoulder dystocia is not advised until more data from randomly assigned trials are available to determine the balance of benefit or harm . Episiotomy does not prevent shoulder dystocia. A systematic review of 14 studies evaluating episiotomy at the time of shoulder dystocia reported conflicting results for neonatal and maternal outcomes when shoulder dystocia was managed with episiotomy . In the review, conclusions regarding the role of episiotomy in the management of shoulder dystocia were further limited because the original studies did not routinely adjust for potential confounders (eg, macrosomia, parity, operative vaginal delivery, and nonrandom study design). (See "Shoulder dystocia: Intrapartum diagnosis, management, and outcome", section on 'Preparation of patient and personnel'.)
●History of female genital cutting (circumcision) – For women with a history of female genital cutting, there may be an increased need for, or at least consideration of, episiotomy during delivery, especially with type III infibulation. The degree or type of female circumcision may result in a significantly narrowed introitus or effectively a tissue bridge overlying the vaginal opening. This may increase difficulty, or entirely eliminate the possibility, of vaginal examinations during labor; result in a soft tissue dystocia during delivery; and increase risk of anterior vaginal, labial, or urethral lacerations during delivery . For these women, episiotomy can be either anterior, posterior (into the perineum), or both . (See "Female genital cutting (circumcision)", section on 'Classification'.)
As high-quality data to guide clinical management are lacking, we provide prenatal or antenatal counseling regarding the options, which include prepregnancy deinfibulation (pending timing of initial visit), antenatal deinfibulation, intrapartum deinfibulation, potential posterior episiotomy to reduce tearing anteriorly, and anterior "episiotomy" with repair to reapproximate the tissue [35,36]. For patients who desire deinfibulation whom we meet during pregnancy, our typical practice is to perform this procedure during the second stage of labor with an anterior "episiotomy" to facilitate delivery and then repair as indicated. For patients who do not desire a deinfibulation and prefer to have the anterior tissue remain approximated, after appropriate counseling with consideration for cultural values, we will base need for anterior separation, perineal episiotomy, or spontaneous laceration on clinical findings during the delivery process, with repair subsequently as indicated.
PROCEDURES AND SELECTION — The most common types of episiotomy are the median (midline) and mediolateral (figure 1). Other less common incisions include the J type and T shape. The decision to perform an episiotomy is a clinical judgement, and routine use of episiotomy is not advised [1,24].
Mediolateral versus median (midline) episiotomy — When performing episiotomy, our preference is a mediolateral episiotomy because it does not increase the risk of an anal sphincter laceration (ie, third- or fourth-degree obstetric injury) as does the median episiotomy [18,19,37]. In order to limit anal sphincter laceration, the Royal College of Obstetricians and Gynaecologists (RCOG) advises mediolateral incisions when episiotomy is performed, and the American College of Obstetricians and Gynecologists states that mediolateral episiotomy may be preferable to median episiotomy in selected cases [27,38]. RCOG recommends that mediolateral episiotomy should be considered in instrumental deliveries as it may have a protective effect .
The selection of median versus mediolateral episiotomy balances the differing risks of the two procedures. Median episiotomy is associated with a higher risk of anal sphincter laceration than mediolateral episiotomy [18,19]. Mediolateral episiotomy is associated with increased blood loss [40,41]. In addition, mediolateral episiotomy has historically been thought to result in more perineal pain and dyspareunia. However, while there are conflicting data, the balance of evidence suggests that there are no differences in pain outcomes between the two procedures [39,42-44]. One study reported greater pain in women with a mediolateral episiotomy incised 60 degrees off the midline compared with women whose episiotomy was cut 40 degrees off of midline, which could partly contribute to the differing study outcomes . Of note, anal sphincter injury itself has been associated with increased perineal pain .
Median (midline) — The median episiotomy starts within 3 mm of the midline of the posterior fourchette and extends downwards between 0 and 25 degrees of the sagittal plane . The median episiotomy is more commonly performed in the United States.
Mediolateral — The mediolateral episiotomy begins within 3 mm of the midline in the posterior fourchette and is directed laterally at an angle of at least 60 degrees from the midline towards the ischial tuberosity . The mediolateral episiotomy is more commonly used in Europe.
J incision — The J incision is less widely used. The incision starts at the fourchette, is initially extended caudally in the midline, and then curved laterally at an angle, similar to the letter J. The anatomical structures incised include the vaginal epithelium, perineal body, and the junction of the perineal body with the bulbocavernosus muscle and perineal skin. Ideally, the transverse perineal muscle is spared because the lateral part of the incision should be below this muscle; however, it is difficult to ensure that it is not incised.
This hybrid of median and mediolateral episiotomies may theoretically optimize the advantages and minimize the disadvantages of the individual techniques. For example, the apex of the incision points away from the rectum to guide any further extension away from this structure. However, there are no data on which to base conclusions.
Other — There are various modifications of the above techniques that may be preferred by individual practitioners (figure 1).
●T episiotomy – The T episiotomy is a modification of the median episiotomy in which bilateral transverse incisions are made at the inferior apex to create an inverted T-shaped incision . This procedure increases the area of the vaginal opening more than a median episiotomy alone (figure 2).
●Lateral episiotomy – The lateral episiotomy is begun at 1 to 2 cm lateral to midline, and the incision is directed laterally toward the ischial tuberosity. It is rarely used.
●Anterior episiotomy – An anterior episiotomy is known as deinfibulation (or defibulation). It is only indicated in the setting of previous female circumcision (ie, female genital mutilation). The fused labia minora are incised in the midline toward the pubis to reveal the external urethral meatus; the clitoral remnants should not be incised. (See "Female genital cutting (circumcision)".)
PERFORMING EPISIOTOMY — Once the decision is made to perform an episiotomy, we obtain verbal consent from the patient, ensure the woman has adequate anesthesia, perform the procedure, and complete the delivery.
Patient education and consent — Ideally, information about perineal laceration and episiotomy is shared with women as part of their prenatal care. Our practice gives women a document reviewing events and procedures that can occur during labor and delivery (eg, cesarean delivery, assisted vaginal delivery, or episiotomy).
We find the following text (or script) helpful in counseling women:
●Many women will get small tears around the vaginal opening. Sometimes a doctor or midwife will cut some tissue to make the opening bigger (episiotomy). Most women with tears or an episiotomy will need stitches. The stitches will dissolve during healing. The area will be swollen and sore for a few days. Rarely, infection may occur. A tear or cut may extend to the rectum. Most often, after repair, this heals with no problems. Rarely, continued problems with bowel movements may occur.
In addition to antenatal education, we verbally consent the patient before performing an episiotomy. In the delivery room, we discuss why we believe the episiotomy will be beneficial to the woman and/or baby, the risks of episiotomy including rectal sphincter injury, and also the risks of not performing episiotomy, such as delayed delivery.
Anesthesia options — A neuraxial anesthetic (ie, spinal or epidural), pudendal block, or local anesthetic (eg, 5 to 20 mL of 1 percent lidocaine injected into the planned episiotomy site) can provide adequate anesthesia for performing an episiotomy. (See "Pudendal and paracervical block", section on 'Pudendal block' and "Neuraxial analgesia for labor and delivery (including instrumented delivery)", section on 'Neuraxial techniques'.)
Timing — A reasonable approach is to perform the procedure when the delivery of the fetus is anticipated within the next three to four contractions. The optimal time for cutting the episiotomy is not known. In a prospective cohort study that compared episiotomy prior to crowning with episiotomy performed at crowning, episiotomy performed prior to crowning was associated with increased vaginal trauma, longer mean episiotomy length, and greater mean estimated blood loss .
Procedure — Prior to performing an episiotomy, the clinician will typically place one or two fingers inside the posterior vaginal wall to protect the fetal scalp during incision. The incision is performed with either scissors or scalpel.
●Median episiotomy – For a median (midline) incision, the perineum is incised vertically within 3 mm of the midline, or at the 6 o'clock position, starting at the introitus (figure 1). The goal is to release any restriction imposed by the perineal body, which can sometimes be felt as a band of tissue cephalad and inferior to the vaginal orifice. The incision is directed internally to minimize the amount of perineal skin incised. The length of the incision is determined by patient anatomy and perceived need. As the general goal of episiotomy is to facilitate delivery of the fetal head, the incision is made long enough to expedite that process but avoid the rectum.
The anatomical structures involved in the incision include the vaginal epithelium, perineal body, and the junction of the perineal body with the bulbocavernosus muscle in the perineum.
●Mediolateral episiotomy – For a mediolateral incision, the incision is made at the vaginal introitus in a lateral direction (figure 1). The incision is initiated at the fourchette and cut at an angle (usually to the maternal right for right handed clinicians) that may be almost perpendicular to the midline (80 to 90 degrees as the fetal head is crowning); however, after delivery of the infant, this angle becomes smaller, approaching 45 degrees, since the perineum is no longer stretched and distorted by the fetal presenting part. The final angle of the incision should be at 30 to 60 degrees from the midline to minimize the occurrence of sphincter injury [49,50]. The incision is usually between 3 and 5 cm in length.
The anatomic structures incised include the vaginal epithelium, transverse perineal and bulbocavernosus muscles, and perineal skin. If the incision is large, adipose tissue within ischiorectal fossa may be exposed.
Delivery and repair — During delivery of the fetal head, support of the perineum at the most interior aspect of the incision may help reduce extensions. (See "Management of normal labor and delivery", section on 'Delivery of the newborn'.)
Following delivery of the fetus and the placenta, a thorough examination of the perineum, including a rectal examination, is performed to determine extent of the incision and any further lacerations or extensions that might warrant repair. Repair of obstetric lacerations and episiotomy incisions is presented separately. (See "Repair of perineal and other lacerations associated with childbirth".)
COMPLICATIONS — Common complications of episiotomy include extension of the incision deeper into the perineum or the anal sphincter complex, infection, breakdown, postpartum pain, and dyspareunia (table 1). Although vulvovaginal hematomas can occur after episiotomies, this complication is rare .
●A prospective, nonrandomly assigned, observational study reported that episiotomy was associated with a 3 cm longer perineal laceration compared with no episiotomy (ie, spontaneous laceration) . Eighty percent of the episiotomies were midline.
●In a meta-analysis of 22 studies, midline episiotomy was associated with nearly four times the risk of obstetric anal sphincter injuries (odds ratio 3.82, 95% CI 1.96-7.42) . Data are less clear for mediolateral episiotomies . In addition to the risk of anal incontinence, obstetric anal sphincter injuries have been associated with postponed coital onset and dyspareunia one year postpartum .
●A case-control study of over 104,000 deliveries reported an incidence of 0.1 perineal laceration breakdowns per delivery (all vaginal deliveries were included) . Episiotomy was an independent risk factor for breakdown of perineal repair (type of episiotomy was not specified).
IMPACT ON FUTURE DELIVERIES — Episiotomy use at the time of first vaginal delivery appears to increase the risk of a severe obstetric laceration in a subsequent vaginal delivery. In a review of over 6000 deliveries that compared women with episiotomy at first delivery versus those without, women with prior episiotomy had a greater number of severe perineal lacerations (4.8 versus 1.7 percent) and more second degree lacerations (51.3 versus 26.7 percent) at the time of subsequent delivery . Logistic regression modeling predicted a fivefold increased risk of anal sphincter complex lacerations for women with prior episiotomy (odds ratio 5.25, 95% CI 2.96-9.32). Although the type of episiotomy was not identified in this study, the majority of episiotomies were likely median incisions as these are most common in the United States, where the study was performed.
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Labor".)
SUMMARY AND RECOMMENDATIONS
●Episiotomy is the surgical enlargement of the posterior aspect of the vagina by an incision to the perineum during the last part of the second stage of labor. The purpose is to widen the birth outlet and facilitate vaginal delivery. (See 'Definition' above.)
●For women undergoing vaginal delivery, we recommend against routine episiotomy (Grade 1B). Routine episiotomy is associated with higher rates of severe perineal trauma and wound complications compared with restricted use of episiotomy. The decision to perform episiotomy is made on a case-by-case, or restricted, basis rather than performing the procedure routinely. (See 'Lack of advantages for episiotomy use' above.)
●Episiotomy may be helpful in some clinical settings. The decision to perform episiotomy is heavily dependent on the opinion of the delivering clinician and is based on the clinical scenario at the time of delivery. There are no specific situations in which episiotomy is essential. Situations in which episiotomy can be helpful include the need for expedited vaginal delivery, operative vaginal delivery, and shoulder dystocia. (See 'When to consider episiotomy' above.)
●When an episiotomy is to be performed, we suggest a mediolateral episiotomy (Grade 2C). Mediolateral episiotomy does not increase the risk of anal sphincter laceration (ie, third- or fourth-degree obstetric injury) as median episiotomy does. (See 'Mediolateral versus median (midline) episiotomy' above.)
●Once the decision is made to perform an episiotomy, patient consent is obtained, adequate anesthesia is provided, and the fetal scalp is protected by the clinician prior to incision. (See 'Performing episiotomy' above.)
•For a median episiotomy, the perineum is incised vertically within 3 mm of the midline, or 6 o'clock position, on the introitus. (See 'Procedure' above.)
•For a mediolateral episiotomy, the incision is made at the vaginal introitus in a lateral direction. (See 'Procedure' above.)
•Documentation of the indication for episiotomy and type performed should be in the delivery record.
●Common complications of episiotomy include extension of the incision into the perineum or anal sphincter complex, infection, postpartum pain, and dyspareunia. (See 'Complications' above.)
●Episiotomy use at the time of the first vaginal delivery appears to increase the risk of a severe obstetric laceration in a subsequent vaginal delivery. (See 'Impact on future deliveries' above.)
ACKNOWLEDGMENT — The editorial staff at UpToDate acknowledge Julian N Robinson, MD, who contributed to an earlier version of this topic review.