Delivery after an obstetric anal sphincter tear

Caesarean section and anal incontinence in women after obstetric anal sphincter injury: A systematic review and meta-analysis

BACKGROUND

Approximately 50% women who give birth after obstetric anal sphincter injury (OASI) develop anal incontinence (AI) over their lifetime.

OBJECTIVE

To evaluate current evidence for a protective benefit of planned caesarean section (CS) to prevent AI after OASI.

SEARCH STRATEGY

MEDLINE/PubMed, Embase 1974-2024, CINAHL and Cochrane to 7 February 2024 (PROSPERO CRD42022372442).

SELECTION CRITERIA

All studies reporting outcomes after OASI and a subsequent birth, by any mode.

DATA COLLECTION AND ANALYSIS

Eighty-six of 2646 screened studies met inclusion criteria, with nine studies suitable to meta-analyse the primary outcome of 'adjusted AI' after OASI and subsequent birth. Subgroups: short-term AI, long-term AI, AI in asymptomatic women.

SECONDARY OUTCOMES

total AI, quality of life, satisfaction/regret, solid/liquid/flatal incontinence, faecal urgency, AI in women with and without subsequent birth, change in AI pre- to post- subsequent birth.

MAIN RESULTS

There was no evidence of a difference in adjusted AI after subsequent vaginal birth compared with CS after OASI across all time periods (OR = 0.92, 95% CI 0.72-1.20; 9 studies, 2104 participants, I2 = 0% p = 0.58), for subgroup analyses or secondary outcomes. There was no evidence of a difference in AI in women with or without subsequent birth (OR = 1.00 95% CI 0.65-1.54; 10 studies, 970 participants, I2 = 35% p = 0.99), or pre- to post- subsequent birth (OR = 0.79 95% CI 0.51-1.25; 13 studies, 5496 participants, I2 = 73% p = 0.31).

CONCLUSIONS

Due to low evidence quality, we are unable to determine whether planned caesarean is protective against AI after OASI. Higher quality evidence is required to guide personalised decision-making for asymptomatic women and to determine the effect of subsequent birth mode on long-term AI outcomes.

Correlation of anorectal symptoms and endoanal ultrasound findings after obstetric anal sphincter injuries (OASIS)

INTRODUCTION

Obstetric anal sphincter injuries (OASIS) predispose to development of anorectal symptoms that affect women's quality of life.

METHODS

A retrospective cohort study was conducted for all women with singleton vaginal deliveries who had a primary OASIS repair and attended the Postpartum Perineal Clinic between July 1st 2017 and December 31st 2020. This study was approved by the Research Ethics Board. The purpose of this study was (1) to determine correlation between endoanal ultrasound (EAUS) findings and anorectal symptoms quantified by the St. Mark's Incontinence Score (SMIS), (2) to determine the incidence of residual anal sphincter defects, and (3) to determine the rate of clinical overdiagnosis of OASIS. Pearson correlation coefficient was used to assess correlation between anorectal symptoms and EAUS findings.

RESULTS

A total of 247 participants with clinical diagnosis of OASIS met the inclusion criteria. A 3rd-degree tear was identified in 126 (51.0%) and 4th-degree tear was identified in 30 (12.1%) participants. In participants with sonographic evidence of OASIS, there was a statistically significant weak positive correlation between the size of residual defect and SMIS for both external anal sphincter (EAS) (r = .3723, p < .0001) and internal anal sphincter (IAS) (r = .3122, p = .0180). Residual defect in the anorectal sphincter of greater than 1 hour (> 30°) in width was present in 64.3% participants with 3rd-degree tear and 86.7% participants with 4th-degree tear. The rate of overdiagnosis was 36.8%.

CONCLUSION

The size of residual defect of EAS and IAS has a weak positive correlation with anorectal symptoms, emphasizing the importance of EAUS for counselling regarding mode of subsequent delivery.

The effects of progesterone on the healing of obstetric anal sphincter damage in female rats

We aimed to evaluate the effects of postpartum progesterone on obstetric anal sphincter injury (OASI) healing in female rats using an experimental OASI model. Twenty-eight female rats were divided into four groups after birth: sham-30, sham-90, progesterone (P4)-30, and P4-90. Moreover, OASI model was established in all groups. Subsequently, except for the sham groups, medroxyprogesterone acetate (0.15 mg) was intramuscularly injected into the P4 groups. After 30 and 90 days, the rats were euthanized under general anesthesia after recording the data. The anal sphincter region was collected for histopathological examination. Progesterone and thiol/disulfide homeostasis studies were performed on blood samples. No significant differences were observed between the groups regarding the external anal sphincter (EAS), internal anal sphincter (IAS), or connective tissue thickness (p = 0.714, p = 0.135, and p = 0.314, respectively). No statistically significant differences in the total thiol, native thiol, disulfide, and progesterone levels were found between the groups (p = 0.917, p = 0.503, p = 0.361, and p = 0.294, respectively). The endometrial thickness was lower in the P4 groups than in the sham groups (p = 0.031). Postpartum progesterone administration did not affect IAS and EAS or connective tissue thickness or disrupt the thiol-disulfide balance. However, this administration led to endometrial thinning.

Implementation of Episcissors-60 for Prevention of Obstetric Anal Sphincter Injuries (OASIS) in a Centre with Low Episiotomy Rates

OBJECTIVE

The purpose of this study was to determine whether introduction of Episcissors-60 into a labour and birth unit would decrease the incidence of Obstetric Anal Sphincter Injuries (OASIS).

METHODS

A before-and-after quality improvement study was conducted between April 1, 2020 and March 31, 2021. All patients who had a vaginal delivery were included in this study. All healthcare providers who perform vaginal deliveries were offered an educational session. Episcissors-60 were then introduced into a labour and birth unit. The primary outcome measure was the change in incidence of OASIS before and after introduction of Episcissors-60. Secondary outcome measures were episiotomy rates before and after introduction of Episcissors-60, device-related adverse events, and provider satisfaction and feedback. Data was analyzed using chi-square tests, independent t-tests, and Mann-Whitney tests.

RESULTS

A total of 1383 vaginal deliveries occurred prior and 1254 vaginal deliveries after introduction of Episcissors-60. There was a decrease in the total OASIS rate from 7.37% of all vaginal deliveries prior to 5.37% after introduction of Episcissors-60 (P = .037). The episiotomy rate was 11.42% prior to and 9.97% after introduction of Episcissors-60 (P = .228). OASIS rate in women who had an episiotomy was 12.02% before and 13.60% after introduction of Episcissors-60 (P = .421).

CONCLUSION

Although introduction of Episcissors-60 was associated with a statistically significant decrease in total OASIS rate, there was no difference in OASIS rates within the subgroup that received an episiotomy. Therefore, reduction in the total OASIS rate in this study cannot be attributed to the use of Episcissors-60.

Risk of obstetric anal sphincter tear among primiparous women with a history of female genital mutilation, giving birth in Sweden

BACKGROUND

Female genital mutilation (FGM) includes a range of procedures involving partial or total removal of the external female genitalia. It is a harmful procedure that violates human rights of girls and women. FGM has been associated with obstetric anal sphincter injury (OASI), among other adverse obstetric complications. However, the obstetric outcomes in high-income countries are not clear. The aim of this study was to compare the risk of OASI among primiparous women, with and without a history of FGM, giving birth in Sweden.

METHOD

A population-based cohort-study based on data from the Swedish Medical Birth Register during the period 2014-2018. The study included primiparous women with singleton term pregnancies. We compared the risk, using multivariable logistic regression, of our main outcome OASI between women with a diagnosis of FGM and women without a diagnosis of FGM. Secondary outcomes included episiotomy and instrumental vaginal delivery.

RESULT

A total of 239,486 primiparous women with a term singleton pregnancy were identified. We included 1,444 women with a diagnosis of FGM and 186,294 women without a diagnosis of FGM in our analysis. The overall rate of OASI was 3% in our study population. By using multivariable logistic regression analysis, we found that women with a diagnosis of FGM had a significantly increased odds ratio (OR) of OASI (OR 2.69, 95%CI: 2.14-3.37) compared to women without a diagnosis of FGM. We also found an association between FGM and instrumental delivery as well as the use of episiotomy.

CONCLUSION

Women with a history of FGM have an almost tripled risk of OASI in comparison with women without FGM, when giving birth in a Swedish setting. Increased knowledge and awareness regarding FGM, and its potential health implications is crucial in order to minimise the risk of OASI among women with FGM giving birth in high-income countries. A limitation in our study is the lack of information about the specific types of FGM.