Pelvic floor trauma in childbirth.

The investigation of female pelvic floor function and anatomy is moving from the fringes to the mainstream of urogynaecology and female urology, and it is becoming increasingly relevant for obstetrics. We are coming to realise that pelvic floor trauma in labour is common, usually overlooked, and a major factor in the causation of pelvic organ prolapse. Modern imaging methods such as magnetic resonance and 3D/4D ultrasound have enabled us to diagnose such trauma reliably and accurately, most commonly in the form of an avulsion of the puborectalis muscle; that is, a disconnection of the muscle from its insertion on the os pubis. Such damage to the levator muscle is macroscopically evident and can also be palpated, a skill that is available to every clinician, requiring neither investment nor specialised equipment. In this review, I will describe pelvic floor assessment by palpation and ultrasound and illustrate the commonest abnormalities and their clinical consequences. This paper will not focus on magnetic resonance imaging due to technical restrictions, cost and access issues in most jurisdictions, and because several papers have recently shown that ultrasound is at least as effective in diagnosing such trauma. Anal sphincter trauma is generally well covered in the literature and hence not subject of this review.