Injury to the perineum during vaginal childbirth affects millions of women. One half to three quarters of parturients undergo some degree of perineal laceration during vaginal childbirth. However, rates vary considerably by locale and provider (Low, 2000; Webb, 2002). Some lacerations occur spontaneously during delivery. Or, an obstetric provider may cut an episiotomy to increase the vaginal outlet size to aid the birth. Either may result in both short- and long-term symptoms and complications. Initially, most women experience at least temporary discomfort or pain after perineal lacerations, and one in five will report long-term issues, such as dyspareunia (Glazener, 1995). Additional complications include physical, psychologic, and social problems, which all may affect a woman's ability to care for her newborn and family (Sleep, 1991). The most severe perineal lacerations involve the anal sphincter, and these are termed obstetric anal sphincter injuries (OASIs). These tears and their consequences are described in detail throughout this chapter.
Preventively, increasing data are available to guide health-care providers and patients in selecting the optimal perineal strategy for each woman's delivery. No single strategy fits all patients, thus clinicians should devote time during antepartum counseling. Topics ideally include discussion of the risks and benefits of episiotomy, strategies that may minimize spontaneous OASIs, and expectations of pelvic floor function following delivery.
In this chapter, we review current literature and practices for antepartum, intrapartum, and postpartum perineal management. Specifically, data regarding risks and possible benefits of episiotomy, repair of obstetric lacerations, and their short- and long-term sequelae are presented.
CLASSIFICATION OF PERINEAL LACERATION
Studies suggest that obstetricians may misclassify anal sphincter injuries. This is coupled with an increasing awareness of the association between OASIs and anal incontinence (Fernando, 2006; Sultan, 1995). For these reasons, the traditional classification system for perineal lacerations was modified to include more specific information regarding the anal sphincter complex. This updated system now contains internationally accepted nomenclature and is summarized in Table 20-1 and Figure 20-1 (Koelbl, 2009; Royal College of Obstetricians and Gynaecologists, 2007).
TABLE 20-1.Classification of Obstetric Lacerations ||Download (.pdf) TABLE 20-1. Classification of Obstetric Lacerations
|Tear Type ||Injury Description |
|First degree ||Injury to perineal skin only |
|Second degree ||Injury to the perineum involving the perineal muscles but not the anal sphincter |
|Third degree ||Injury involves anal sphincter complex |
| 3a ||Less than 50% of EAS is torn |
| 3b ||More than 50% of EAS is torn |
| 3c ||EAS and IAS are torn, but the anorectal epithelium is intact |
|Fourth degree ||EAS, IAS, and anorectal epithelium are torn |
1. First-degree perineal laceration: injury only to perineal skin. 2. Second-degree perineal laceration: injury to perineum involving the perineal muscles but not to the anal sphincter complex. 3a. Third-degree perineal laceration: less than 50% of the external ...