Pelvic Floor Trauma in Childbirth

Between 4 and 40% of women will suffer permanent pelvic floor trauma in childbirth. Irreversible damage to the pelvic floor at the time of vaginal birth may take the form of trauma to the levator ani complex or obstetric anal sphincter injury (OASI). Long-term sequelae include pelvic organ prolapse, its recurrence after surgical repair, urinary and fecal incontinence, sexual dysfunction and chronic pelvic pain. Detection rates are poor, especially for levator ani trauma, which is often clinically undetectable at the time of vaginal birth. Translabial ultrasound is an objective method for the diagnosis of irreversible pelvic floor trauma and was used in observational studies for this thesis. Original studies undertaken for this thesis showed antenatal risk factors for levator avulsion include increasing maternal age (OR 1.05, p=0.019), lower body mass index (BMI; OR 0.94, p=0.018), and increasing bladder neck descent (BND; OR 0.97, p=0.026). Intrapartum risk factors identified include longer second stage (OR 1.02, p=0.01), OASI (OR 3.2, p= 0.002), and the use of forceps (OR 2.9, p=0.001). The latter is by far the strongest modifiable risk factor and should be avoided. Predictors of atraumatic normal vaginal delivery were younger maternal age (OR 0.93, p