Screening occult anal sphincter injuries in primigravid women after vaginal delivery with transperineal use of vaginal probe: a prospective, randomized controlled trial

Abstract

Here, we found that only a portion of anal sphincter injuries can be detected after physical examination, with many of cases of "occult tears" escaping notice. These cases of occult anal sphincter injury are detectable by sonography with transperineal use of a vaginal probe. Based on these findings, we propose that this technique is convenient for obstetric, gynecologic and proctologic evaluation of sphincter anatomy.

Does the Epi‐No® birth trainer prevent vaginal birth‐related pelvic floor trauma? A multicentre prospective randomised controlled trial

“…In this study, we observed a 6.2% incidence of clinical major perineal tears and 17.6% sonographically diagnosed OASIS. This is comparable with the 0.5–6.6% and 15–35% incidence of clinically and sonographically diagnosed OASIS reported by previous studies . The discrepancy between clinical and sonographic OASIS prevalence may result from clinical under‐diagnosis or truly ‘occult’ tears .…”

“…Andrew et al reported that diagnoses of OASIS were being missed by midwives, senior house officers, and specialist registrars in 87, 67, and 14% of deliveries, respectively . Previous studies have claimed a 1.2–13.4% overall prevalence of occult anal sphincter injury . The marginally increased risk of sonographically diagnosed EAS defect in the intervention group (21 versus 14%; RR 1.44, 95% CI 0.95 to 2.20; P = 0.07) observed in our study may be a spurious finding, as we are not aware of any pathophysiological mechanism that could explain such an association.…”

“…Other vaginal birth‐related injuries include perineal tears and obstetric anal sphincter injuries (OASIS). The usually quoted incidence of OASIS ranges from 0.5 to 5%, but is likely to be much higher as the diagnosis is frequently missed in the delivery suite . These injuries may result in chronic morbidity such as FPOP, anal incontinence, perineal pain, dyspareunia, and sexual dysfunction, often involving long latency between trauma and subsequent morbidity, impairing women's quality of life (QoL) .…”

Clinical and methodological aspects on perineal laceration diagnostics at childbirth

“…The incidence of IAS injury varies in studies, and in most studies on OASIS, the IAS is not mentioned at all. Ozyurt et al (54) studied 201 primiparous women with transperineal ultrasound after delivery before hospital discharge. Seven women had an OASI and two had an IAS injury (28%).…”

“…To our knowledge, all research on these modalities has studied conditions after primary repair or in long-term follow-up-studies, but no studies have been performed before primary repair. However, in the postpartum period it is stated that transperineal (29,53,54) or transvaginal (55) examination is useful in identifying normal anatomy with high specificity but low sensitivity, especially for endovaginal ultrasound with a rotating probe (43). A few studies have compared the endoanal and transvaginal (56)(57)(58)(59)(60) or transperineal (61)(62)(63)(64) approaches, suggesting these to be feasible alternatives in clinical practice.…”