Third‐ and fourth‐degree tears: A review of the current evidence for prevention and management

Abstract

Background: Third-and fourth-degree tears are associated with significant pain, discomfort and impact on quality of life and intimate relationships. Australian women experience comparatively higher rates of third-and fourth-degree tears relative to countries of similar economic development. Aims:We aimed to conduct a comprehensive review of the literature, published over the past five years, to identify the best ways to prevent and manage third-and fourth-degree perineal tears in Australian maternity centres. Materials and Methods:We searched the literature using the Cochrane Database of Systematic Reviews, EMBASE, MEDLINE, Maternity and Infant Care Database and Google Scholar for articles published since 2013 using key search terms. A review of reviews was undertaken given the extensive amount of literature on this topic. Results: Twenty-six systematic reviews were identified. The most common risk factors reported in the literature for third-and fourth-degree tears included primiparity, mother's ethnicity, large for gestational age infants and certain interventions used in labour and birth, such as instrumental deliveries. Preventive practices with varying degrees of effectiveness and often dependant on parity included: antenatal perineal massage, different maternal birthing positions, water births, warm compresses, protection of the perineum and episiotomy for instrumental births.Conclusions: Third-and fourth-degree perineal tears are associated with immediate and long-term implications for women and health systems. Evidence-based approaches can reduce the number of women who sustain a severe perineal tear and alleviate the associated disease burden for those who do. K E Y W O R D Schild birth, obstetric labour complications, perineal tears, perineum, pregnancy SUPPORTING INFORMATIONAdditional supporting information may be found online in the Supporting Information section at the end of the article. Table S1. Systematic reviews.

Risk Factors in Third and Fourth Degree Perineal Tears in Women in a Tertiary Centre: An Observational Ambispective Cohort Study

“…The induction of labor is also associated with an increased risk of severe tearing. Wilson et al [17] in a review with an N of more than 400,000 women, presented a very similar risk of third and fourth degree tears (OR = 1.08; p = 0.01) to the result presented in our study (OR = 1.29; p = 0.047).…”

Recovery from Obstetric Anal Sphincter Injury in a Prospective Cohort of First Births

“…Our study affirms maternal and obstetric characteristics associated with OASIS noted in previous work, including race/ethnicity, age, episiotomy, operative delivery, and shoulder dystocia. 1 2 4 5 6 7 8 Unlike prior studies, 7 high infant birth weight was not associated with OASIS in our sample; this may reflect increasing rates of cesarean delivery in cases of suspected macrosomia or other indicators of a difficult vaginal delivery. 27 The finding that women with OASIS were at increased risk of accidental stool loss at 1-month postpartum is consistent with prior literature.…”

“…A robust body of research has identified risk factors for OASIS which include nulliparity, operative vaginal delivery, routine use of episiotomy, higher fetal birth weight, shoulder dystocia, labor induction and augmentation, and use of epidural analgesia. 1,2,[4][5][6][7][8] OASIS was previously examined as an obstetric quality measure but ultimately eliminated, as several risk factors for severe lacerations are not modifiable. Additionally, avoiding one of the key risk factors, operative vaginal delivery, may increase cesarean delivery.…”

Trends in and Factors Associated With Episiotomy in the Setting of Nonoperative Vaginal Delivery, 2000–2018

“…It can be emphasized that episiotomy has an even lower statistical risk for severe perineal injury than primiparity, large birth weight, or instrumental delivery. 5 We also dispute that this study's findings suggested that episiotomy was required in a small minority of vaginal deliveries. It showed only that they occurred in a small minority of vaginal deliveries.…”