Prevention of Perineal Injury During the Second Stage of Labor
September 1, 2022
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By Ahizechukwu C. Eke, MD, PhD, MPH
Associate Professor in Maternal Fetal Medicine, Division of Maternal Fetal Medicine, Department of Gynecology & Obstetrics, Johns Hopkins University School of Medicine, Baltimore
SYNOPSIS: This randomized clinical trial in nulliparous women demonstrated that the hands-off technique reduced the risk for perineal injuries when compared to the hands-on technique during the second stage of labor.
SOURCE: Califano G, et al. Hands-on vs hands-off technique for the prevention of perineal injury: A randomized clinical trial. Am J Obstet Gynecol MFM 2022; Jun 10:100675. doi: 10.1016/j.ajogmf.2022.100675. [Online ahead of print].
Perineal lacerations are common during the second stage of labor. When they occur, they commonly involve the vaginal epithelium and/or perineal body (mild type), but occasionally they can involve the anal sphincter and/or the anus (severe type). The prevalence of perineal lacerations varies from approximately 69% in multiparous women to 90% in nulliparous women.1 Although there are known risk factors that predispose patients to perineal lacerations, including but not limited to fetal macrosomia, fetal malpresentations and malpositions, instrumental deliveries, persistent occipito-posterior position, precipitate labor, and nulliparity, perineal lacerations still can occur in the absence of risk factors.1-4 Perineal lacerations are classified into four categories based on the degree of involvement of the perineal organs: first-degree perineal laceration involves the vaginal mucosa and perineal skin, second-degree perineal laceration involves the perineal body, third-degree perineal laceration involves the anal sphincter, and fourth-degree perineal laceration involves the anal mucosa. Third-degree lacerations are further subclassified as stages 3A and 3B if < 50% or > 50%, respectively, of the external anal sphincter is involved, and as stage 3C if both the external and internal anal sphincters are involved.5 Third- and fourth-degree perineal lacerations also are referred to as obstetric anal sphincter injuries (OASIS). OASIS is important because, if not properly managed, it can lead to long-term complications, such as chronic pain, flatus, and fecal incontinence, which can affect a woman’s quality of life.4 Hence, preventing OASIS is critical during the second stage of labor.
Several techniques have been advocated for preventing perineal lacerations during the second stage of labor. Prominent among these methods is the use of perineal support (hands-on approach) or a hands-off approach.6 Although both management approaches have been used with varied success, studies are conflicting on the significant benefit of the hands-on approach compared to the hands-off approach for preventing perineal lacerations.7 In this paper, Califano and colleagues sought to evaluate if the hands-off technique would reduce the rate of perineal lacerations during spontaneous vaginal delivery compared to the hands-on method.8
This was an open-label, randomized clinical trial conducted at a single academic center — the University of Naples Federico II, in Naples, Italy, between May 2021 and December 2021. Nulliparous women with singleton gestations, with fetuses in vertex presentation, admitted into labor and delivery for active phase of labor between 37 0/7 weeks of gestation and 42 0/7 weeks of gestation met eligibility criteria. Multiparous women, women with multiple gestation, preterm labor, post-term labor, preterm premature rupture of membranes, prior cesarean delivery, induction of labor with either oxytocin or cervical ripening, hypertensive disorders of pregnancies, diabetes, intrauterine growth restriction, and fetal abnormalities were excluded. Participants were randomized in a 1:1 ratio to receive either the hands-off technique (intervention group) or the hands-on technique (defined by the authors as the application of pressure to the fetal head with one hand to control expulsion and application of pressure on the perineum by the other hand to prevent perineal injuries) during pushing in the second stage of labor. The primary outcome was the rate of any degree of perineal laceration (first-, second-, third-, or fourth-degree). The secondary outcomes were the rates of OASIS and episiotomy. A total sample size of at least 70 nulliparous women with singleton gestations (35 women per group) was sufficient to demonstrate a 50% reduction in the rate of the primary outcome (assuming a baseline incidence of 73% rate of the primary outcome in the control group [the hands-on technique]), and assuming 80% power and a type 1 error rate of 5%.
From May 2021 to December 2021, 109 nulliparous pregnant women with singleton gestations met inclusion criteria, out of which 70 women ended up being randomized. Thirty-five participants received hands-off management and 35 participants received hands-on management. The baseline characteristics were similar in the two groups. The incidence of the primary outcome (perineal laceration of any degree) was lower in the hands-off group compared to the hands-on group (42.9% vs. 94.3%), for a risk ratio (RR) of 0.45 (95% confidence interval [CI], 0.31, 0.67; P < 0.05). The rates of first-degree (RR, 0.41; 95% CI, 0.20, 0.87; P < 0.05) and second-degree (RR, 0.43; 95% CI, 0.19 to 0.99; P < 0.05) perineal lacerations also were significantly lower in the hands-off group. Although the hands-off technique was associated with a significantly decreased risk of episiotomy (RR, 0.36; 95% CI, 0.14 to 0.88; P < 0.05), there were no significant differences in third- and fourth-degree lacerations between the two groups.
COMMENTARY
This study demonstrated that the hands-off approach reduced the risk for perineal injuries when compared to the hands-on technique during the second stage of labor. When perineal lacerations occur, not all need to be sutured (especially if mild), since there is limited evidence to recommend surgical repair over nonsurgical approaches for the management of mild lacerations that occur during the second stage of labor.9 In fact, some studies have demonstrated that suturing perineal lacerations after vaginal delivery can interfere with first breastfeeding.10 The positives of nonsurgical management include spontaneous healing ability, reduced pain, early ambulation, and early commencement of breastfeeding; negatives include the risk for prolonged wound healing, chronic pelvic pain, and incontinence.10 Hence, selection of cases for nonsurgical management should be done carefully and selectively.
Episiotomies were used traditionally to decrease the risk for perineal lacerations, especially when the risk for OASIS is increased, but the evidence for the routine use of episiotomy during the second stage of labor is conflicting.11 Although some studies have demonstrated that prophylactic episiotomy can be protective, other studies have shown deleterious effects.12,13 Overall, an episiotomy still may be indicated to relieve tissue dystocia, to assist an operative vaginal delivery or shoulder dystocia, or to expedite delivery of the fetus in cases of fetal intolerance of labor. Otherwise, routine episiotomies do not decrease the risk of perineal lacerations and can be harmful.
The principles of repairing obstetric anal injuries involve the use of good lighting, adequate analgesic, and adequate perineal exposure.14 Repair of OASIS using the “PISA” (posterior, inferior, superior, and anterior) technique is recommended for easy visibility and closure. At the time of repair, 1 g of cefoxitin or cefotetan or 900 mg of clindamycin (for allergic patients) is recommended.14 After repair of OASIS, stool softeners (e.g., polyethylene glycol or docusate sodium) are recommended for a period of three to six weeks to prevent the passage of hard stools that could result in perineal wound dehiscence. Pelvic floor exercises are encouraged in the postpartum period, since these exercises have been shown to reduce the rate of urinary, flatus, and fecal incontinence following repair of OASIS. Fortunately, 60% to 80% of women are asymptomatic one year following a delivery complicated by OASIS.2 There is limited evidence on the optimal time to resume sexual activity after OASIS. The evidence for an elective cesarean delivery in a future pregnancy as the result of a prior history of OASIS is mixed.15
In summary, the findings from this study are unlikely to change practice, since the sample size is small (more studies are needed to validate this finding) and application of perineal pressure can be provider-dependent, which can affect how perineal lacerations occur. The American College of Obstetricians and Gynecologists (ACOG) does not recommend the routine use of episiotomies to prevent perineal lacerations, and advises that clinical judgment remains the best guide for the use of episiotomies.5 Since OASIS can occur in the absence of risk factors, physicians should be trained on early detection, prompt management, and appropriate follow-up of OASIS cases.
REFERENCES
- Goh R, et al. Perineal tears - A review. Aust J Gen Pract 2018;47:35-38.
- Evans E, et al. What is the total impact of an obstetric anal sphincter injury? An Australian retrospective study. Int Urogynecol J 2020;31:557-566.
- Villot A, et al. [Management of third and fourth degree perineal tears: A systematic review]. J Gynecol Obstet Biol Reprod (Paris) 2015;44:802-811.
- Wilson AN, et al. Third- and fourth-degree tears: A review of the current evidence for prevention and management. Aust N Z J Obstet Gynaecol 2020;60:175-182.
- Committee on Practice Bulletins-Obstetrics. ACOG Practice Bulletin No. 198: Prevention and management of obstetric lacerations at vaginal delivery. Obstet Gynecol 2018;132:e87-e102.
- Vieira F, et al. Scientific evidence on perineal trauma during labor: Integrative review. Eur J Obstet Gynecol Reprod Biol 2018;223:18-25.
- Bulchandani S, et al. Manual perineal support at the time of childbirth: A systematic review and meta-analysis. BJOG 2015;122:1157-1165.
- Califano G, et al. Hands-on vs hands-off technique for the prevention of perineal injury: A randomized clinical trial. Am J Obstet Gynecol MFM 2022; Jun 10:100675. doi: 10.1016/j.ajogmf.2022.100675. [Online ahead of print].
- Elharmeel SM, et al. Surgical repair of spontaneous perineal tears that occur during childbirth versus no intervention. Cochrane Database Syst Rev 2011;CD008534.
- Lundquist M, et al. Is it necessary to suture all lacerations after a vaginal delivery? Birth 2000;27:79-85.
- Carroli G, et al. Episiotomy for vaginal birth. Cochrane Database Syst Rev 2009;CD000081.
- Vale de Castro Monteiro M, et al. Risk factors for severe obstetric perineal lacerations. Int Urogynecol J 2016;27:61-67.
- Shmueli A, et al. Episiotomy - risk factors and outcomes. J Matern Fetal Neonatal Med 2017;30:251-256.
- Meister MR, et al. Techniques for repair of obstetric anal sphincter injuries. Obstet Gynecol Surv 2018;73:33-39.
- Harvey MA, et al. Obstetrical anal sphincter injuries (OASIS): Prevention, recognition, and repair. J Obstet Gynaecol Can 2015;37:1131-1148.
This randomized clinical trial in nulliparous women demonstrated that the hands-off technique reduced the risk for perineal injuries when compared to the hands-on technique during the second stage of labor.
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