Sonographic postpartum anal sphincter defects and the association with pelvic floor pain and dyspareunia

Acta Obstet Gynecol Scand. 2023 Oct;102(10):1290-1297. doi: 10.1111/aogs.14606. Epub 2023 Jun 23.


Introduction: Pelvic floor pain and dyspareunia are both important entities of postpartum pelvic pain, often concomitant and associated with perineal tears during vaginal delivery. The association between postpartum sonographic anal sphincter defects, pelvic floor pain, and dyspareunia has not been fully established. We aimed to determine the prevalence of postpartum anal sphincter defects using three-dimensional endoanal ultrasonography (3D-EAUS) and evaluate their association with symptoms of pelvic floor pain and dyspareunia.

Material and methods: This prospective cohort study followed 239 primiparas from birth to 12 months post delivery. Anal sphincters were assessed with 3D-EAUS 3 months postpartum, and self-reported pelvic floor function data were obtained using a web-based questionnaire distributed 1 year after delivery. Descriptive statistics were compared between the patients with and without sonographic defects, and the association between sonographic sphincter defects and outcomes were analyzed using logistic regression.

Results: At 3 months postpartum, 48/239 (20%) patients had anal sphincter defects on 3D-EAUS, of which 43 (18%) were not clinically diagnosed with obstetric anal sphincter injury at the time of delivery. Patients with sonographic defects had higher fetal weight than those without defects, and a perineum <2 cm before the suture was a risk factor for defects (odds ratio [OR], 6.9). Patients with sonographic defects had a higher frequency of dyspareunia (OR, 2.4), and pelvic floor pain (OR, 2.3) than those without defects.

Conclusions: Our results suggest an association between postpartum sonographic anal sphincter defects, pelvic floor pain, and dyspareunia. A perineal height <2 cm, measured by bidigital palpation immediately postdelivery, was a risk factor for sonographic anal sphincter defect. We suggest offering pelvic floor sonography around 3 months postpartum to high- risk women to optimize diagnosis and treatment of perineal tears and include perineum <2 cm prior to primary repair as a proposed indication for postpartum follow-up sonography.

Keywords: anal sphincter defect; dyspareunia; pelvic floor; perineal pain.