Vaginal birth and Pelvic Floor Disorders. If the structure fails does anyone care? (Video) Event as iCalendar


08 March 2016

4 - 5pm

Venue: Ground Floor Seminar Room (G10)

Location: 70 Symonds St

Prof John DeLancey, University of Michigan

Abstract: If we knew that 1 in 15 healthy women was being injured, we would do something to help prevent these injuries.  In fact we do know that. It is birth-related pelvic floor injury that happens in our hospitals every day yet little has been done to prevent these injuries because the basic nature of the injuries have been unknown.  During the last 20 years Biomechanical Engineers and Gynecologist/Anatomists in our Pelvic Floor Research Group have been trying to understand how vaginal birth leads to pelvic organ prolapse and urinary incontinence; conditions referred to as pelvic floor disorders.  These problems affect 300,000 women so severely that they require surgery in the US.  This presentation will describe the ways in which we have approached these problems.  It was necessary to understand the pathophysiology of prolapse and incontinence and then to see which features of vaginal birth and what injuries occurred that were related.  We discovered an injury to the levator ani muscle that occurred as a result of vaginal birth and then demonstrated that it was found in 55% of women with prolapse but only 16% of women with normal support.  Our work on birth was then directed to identify causal pathways for this injury.  This work started with anatomically-based geometric simulations of birth that indicated that injuries occurred in regions that had the highest muscle strain ratios.  We then investigated the interactions between the head and the amount of soft tissue deformation that was involved as well as time-dependent properties of these remarkable tissues.  MRI studies were needed to decide between the three competing hypotheses for muscle injury; nerve injury, muscle compression, stretch-induced tearing.  Nerve injury and compression were rejected confirming that muscle stretch is the primary cause.  This has direct clinical impact because the compression and nerve injury hypotheses were used to justify shortening the length of time that the head compressed the pelvic floor and nerves.  Forceps delivery was used to do this that actually increases injury.  We are now working on capacity-demand analysis; a strategy that will allow us to estimate a woman’s risk for injury and soon that can allow women to consider their likelihood of having an injury and take that into account while making decisions about how they hope to give birth.