OC12.04: Engagement of the fetal head evaluated by perineal ultrasound in pregnancies with prelabor rupture of membranes

Abstract

issues involved, including health economics and the relative roles of healthcare providers, the discussion surrounding pelvic floor trauma in childbirth has not always been completely rational. However, after 25 years of urogynaecological research in this field it appears that there are sufficient grounds to state that vaginal delivery (or even the attempt at vaginal delivery) can cause damage to the pudendal nerve, the inferior aspects of the levator ani muscle and fascial pelvic organ supports. Ultrasound imaging has been very useful in defining the effect of delivery on pelvic organ mobility and levator function, and, most recently, has helped define specific forms of morphological alterations that occur in labour. Amongst those are disruption of the rectovaginal septum and of paravaginal supports, attenuation or disruption of the pubocervical fascia and avulsion of the levator ani off the pelvic sidewall. As most of this data is very recent, the clinical relevance of such trauma is less clear. Increased bladder neck descent after vaginal delivery has been shown to be associated with de novo or worsened stress incontinence postpartum, and bladder neck descent is associated with urodynamics stress incontinence in later life. However, in epidemiological studies the effect of childbirth seems to disappear beyond the age of 55–60, most likely due to the impact of other aetiological factors. As regards pelvic organ prolapse, epidemiological studies have shown that vaginal parity is consistently the strongest determinant of prolapse. One possible aetiological factor is levator avulsion injury, and it has recently been shown that the presence of levator avulsion in older, symptomatic women is strongly associated with prolapse of the anterior and central compartment, i.e., with cystocele and uterine prolapse. In conclusion, pelvic floor trauma in childbirth is not a myth, it is reality, and diagnostic ultrasound is playing a major role in elucidating aetiological pathways. As we are now able to assess pelvic floor biomechanics, predicting such trauma may soon become possible, enabling us to prevent future pelvic floor problems such as stress urinary incontinence and pelvic organ prolapse.