Obstetric anal sphincter injury, risk factors and method of delivery – an 8-year analysis across two tertiary referral centers

Abstract

These results demonstrate that OASIS remains an important cause of maternal morbidity in contemporary obstetric practice. These results will likely be of value in risk management planning and patient debriefing in what is a highly litigious area of obstetrics.

Long‐term outcomes of the Stop Traumatic OASI Morbidity Project (STOMP)

“…Both forceps and vacuum delivery are known to be significant risk factors for OASI . In the present study, the OASI rate decreased significantly for both spontaneous deliveries and instrumental deliveries, which demonstrates that the STOMP principles applied at delivery can mitigate the risk of OASI even for deliveries that carry a higher overall risk.…”

Normal values for high‐resolution anorectal manometry/topography in a healthy Korean population and the effects of gender and body mass index

“…The effect of vaginal delivery on anorectal function and defecation disorder is an important clinical issue . Our present findings in this regard in asymptomatic adults indicate that vaginal delivery is not independently associated with any anorectal HRM parameter.…”

“…Recently, a study has reported the association between BMI and anal pressures measured using conventional anorectal manometry . In addition, the vaginal‐delivery history is thought to affect anorectal parameters, as there have been a number of reports regarding defecation disorder and FI following delivery . However, detailed analyses of the influence of BMI and vaginal delivery on anorectal physiology are scarce.…”

“…Multivariate linear regression analysis was performed to identify the independent effects of each factor. Key Results Anal resting pressure (median [IQR]; 32 [18] vs 46 [17] mmHg, p < 0.001), anal squeeze pressure (75 [28] vs 178 [72] mmHg, p < 0.001), rectal pressure (33 [16] vs 53 [46] mmHg, p = 0.009) and anal pressure (16 [17] vs 30 [36] mmHg, p = 0.019) during simulated evacuation with rectal distention, and the threshold for the desire to defecate (60 [20] vs 80 [60] mL, p = 0.020) were significantly lower in women than in men. BMI was positively correlated with anal resting pressure (95% CI: 0.598-2.947) and negatively correlated with the threshold for first sensation (95% CI: À0.099 to À0.015).…”

A comparative study of obstetric anal sphincter injuries in vaginal deliveries of twins and singleton pregnancies

“…The most significant long term morbidity arises from third and fourth degree perineal tears, commonly called obstetric anal sphincter injuries (OASIS) . It has been demonstrated that the OASIS complicates 1.3% of natural vaginal deliveries, 3.7% of vacuum deliveries and 8.6% of forceps deliveries . Numerous studies have attempted to identify risk factors associated with OASIS following vaginal delivery of singletons .…”