Passive management of labour may predispose to anal sphincter injury

A systematic review and a meta-analysis on the incidence of obstetric anal sphincter injuries during vaginal delivery

AIM

The incidence of obstetric anal sphincter injuries (OASIS) has increased in the past two decades despite improved awareness of the risk factors. This study aimed to define the incidence of OASIS in women with different features (instrumental delivery or other variables).

METHODS

A systematic review was conducted on articles reporting the incidence of OASIS. This review aims to examine the association of instrumentation and OASIS by performing a formal systematic review of the published literature. Databases used for the research were MEDLINE, Embase, CINAHL and 'Maternity and infant care' databases.

RESULTS

Two independent reviewers screened the selected articles. 2326 duplicates were removed from the total of 4907 articles. The remaining 2581 articles were screened for title and abstract. 1913 articles were excluded due to irrelevance. The remaining 300 were screened as full text. Primiparity associated with the use of forceps were the features associated with the highest incidence of OASIS in the selected articles (19.4%). OASIS in all women had an overall incidence of 3.8%. The incidence of OASIS in all women by geographical region was the highest (6.5%) in North America.

CONCLUSIONS

There are various factors that impact on the incidence of OASIS and the combination of some of these, such as the use of forceps in primiparas, resulted in the highest incidence of OASIS. The lack of international consensus is limiting the improvements that can be done to reduce OASIS rates and improve best clinical practice.

Have we lost sight of the women? An observational study about normality-centred care in Australian maternity services

BACKGROUND

Prioritising normal birth has led to harm in some instances in the United Kingdom. While Australian organisations also promote normal birth, its negative impact is less well understood here.

AIMS

This study explores the problems that may arise from the promotion of normal birth and the quality of clinical incident investigations.

MATERIALS AND METHODS

This study uses a survey-based research design and has received 1278 responses. The main outcome measures include perceptions on bias against interventions, delays in interventions, systemic attempts to reduce caesarean rates, and clinical incident investigations.

RESULTS

The perception among both obstetric and midwifery cohorts is that the promotion of normal birth may sometimes or frequently lead to bias against intervention for women (93.8% vs 63.2%), bias against intervention for clinicians (81.1% vs 53.1%), delays in interventions (86.8% vs 37.4%), maternal request caesarean sections being discouraged (81.2% vs 66.9%), an increased emphasis on vaginal birth after caesarean (88.1% vs 69.3%), and a culture of vaginal births 'at all costs' leading to poor outcomes for mothers and babies (79.5% vs 24.7%). Respondents believe clinical incident investigations to be 'frequently' independent (48% vs 48.2%) but engagement of women in these processes is often missing or 'rarely' seen (46.6% vs 51.7%).

CONCLUSIONS

This study finds that Australian maternity healthcare providers believe institutional encouragement of normal birth has created work practices in maternity care that compromise patient safety and reduce the agency of the woman in the choices she makes. Current regulatory standards must change to reflect core ethical and legal obligations around informed consent.

A biomechanically based concept for a stronger obstetric anal sphincter repair

INTRODUCTION AND HYPOTHESIS

This study emanates from the ISPP OASIS and fecal incontinence study group at the 2018 annual meeting of the International Society for Pelviperineology (ISPP) in Bucharest, Romania. The aim was to analyze the biomechanical factors leading to the breakdown of anal sphincter repair and to suggest a more robust technique for external anal sphincter (EAS) repair.

METHODS

Our starting point was what happens to the EAS wound repair site during defecation following EAS repair, with special reference to the process of wound healing.

RESULTS

We concluded that a graft no more than 1 × 1.5 cm sutured across the EAS tear line would mechanically support the tear line, vastly reduce the internal centrifugal forces acting on it during defecation, thereby giving the wound time to heal. Three different grafts were discussed, autologous, biological, and mesh. Also analyzed were the effects on EAS muscle contractility of overly tight repair and overly loose sphincter repair, the latter occasioned by the tearing out of sutures and repair by secondary intention.

CONCLUSIONS

We have analyzed causes of sphincter repair failure, introduced a graft method, preferably autologous, for the prevention thereof and supported ultrasound assessment, rather than the absence of fecal incontinence as the criterion for success of EAS repair. Although based on well-established biomechanical principles, our proposal at this stage remains unproven. Our hope is that these concepts will be challenged, clarified, and tested, preferably in a randomized controlled trial.