Evaluation of isolated urinary stress incontinence according to the type of levator ani muscle lesion using 3/4D transperineal ultrasound 36 months post-partum

Introduction Vaginal delivery can lead to pelvic floor disorders. Many authors have described pelvic floor injuries that can predict future defects such as urinary incontinence and pelvic organ prolapse. We propose the assessment of urinary stress incontinence and its association with levator ani muscle (LAM) microtrauma (>20% in the levator hiatus area during Valsalva) and macrotraumas (avulsion) identified by 3/4D transperineal ultrasound (3D-TpUS) 36 months post-partum. Materials and methods This was a prospective observational study including 168 nulliparous women. All patients included were nulliparous with singleton gestation in cephalic presentation, at ≥37 weeks and were recruited on the first day after delivery. Thirty-six months after delivery, 3D-TpUS was carried out to identify LAM lesions (macro or micro). Clinical assessment of urinary stress incontinence (USI) was based on the ICIQ-UI-SF test; a simple stress test and urodynamic test were carried out in the same visit. Results A total of 105 nulliparous women were studied (51 spontaneous deliveries [SpD] and 54 vacuum-assisted deliveries [VD]). Microtraumas were identified in 35.3% of SpD and 20.4% of VD. Macrotraumas (avulsion) were identified in 9.8% of SpD and 35.2% of VD ( p = 0.006). No differences were found in USI between study groups or in relation to the identification of LAM defects (19.2% in the no lesion group, 25% in the macrotrauma and 13.8% in the microtrauma groups; p = not significant). Nor were significant differences found in the results from the different study groups in the International Consultation on Incontinence Modular Questionnaire Urinary Incontinence Short Form (ICIQ-UI SF) test (12.7±2.2 in the no lesion group, 12.5±4.2 in the macrotrauma and 13.25±4.8 in the microtrauma groups; p = NS). Conclusion No difference was observed in USI between patients with and without LAM lesions (microtrauma or macrotrauma) 36 months post-delivery.