1 FEMALE PELVIC FLOOR IMAGING: THE IMPACT OF PREGNANCY ON PELVIC ORGAN SUPPORT Caitlyn McCann, Steven Abramowitch PhD, Timothy Canavan MD, & Pamela Moalli MD, PhD University of Pittsburgh and Magee-Women’s Research Institute & Foundation INTRODUCTION Pelvic organ prolapse (POP) is the downward descent of the female pelvic organs, such as the bowel, bladder or uterus, into the vagina 1 . Pelvic organ descent progresses in a slow maner and ultimately results in varying degrees of physical discomfort. Women suffereing from POP often complain of urinary incontinence, difficult urination and defecation, low back pain, or feelings of pelvic pressure 2,3 . In addition, women suffering from POP may also experience emotional distress 4 . The physical and emotional toll associated with POP has a devastating impact on the quality of life of millions of women around the world. In the United States alone, over 10% of women undergo surgery to repair prolapse with the cost of prolapse surgery estimated around 1 billion dollars annually 5 . As the population continues to age, it is projected that the number of U.S. women suffering from POP will increase from 3.3 million in 2010 to 4.9 million in 2050, which is a 46% increase over the 40 year period 4 . While many factors, such as aging and increasing body-mass index, are believed to contribute to the cause of the disorder, the most significant risk factor associated with pelvic organ prolapse is pregnancy 1,6 . As a result, many women are choosing to undergo Ceserian deliveries as a means of preventing prolapse. Currently, there is no research data that supports this preventative strategy due to the fact that only a few studies have characterized pelvic organ support changes during pregnancy 7 . Recently, the use of ultrasound equipment has made it easier to investigate changes in the pelvic floor. In the past, diagnostic imaging was not used to view the pelvic floor due to poor quality imaging and the high cost of equipment. Today, the use of ultrasound to view the pelvic floor provides physicians and researchers with several advantages due to its ready availability, ease of use, and non-invasive nature 8 . OBJECTIVE Based on a lack of knowledge surrounding the main risk factor associated with prolapse, as well as the lack of studies involving the use of ultrasound to view the pelvic floor, the objective of the present study was determined. The present study aims to use ultrasound images to gain a better understanding of the anatomical differences of the pelvic floor at the different stages of pregnancy. SUCCESS CRITERIA In order to determine if the objective of the project has been statisfied, several criteria must be met. Minimal differences must result between intra- and inter-repeatabilily measurements. Additionally, measurements must be accurate. METHODS Midsaggetal and axial ultrasound images were acquired from a sample of 25 healthy females from Magee-Womens Hospital of UPMC. Inclusion creterion encompassed several factors such as 1) Pregnancy must be the woman’s first; 2) Must have the intention to deliver at the study site hospital; 3) Must be over the age of 18. The number of ultrasound images taken varied anywhere from 3 images to 9 images per participant. An imaging process software (OsiriX) was used to view the ultrasound images. Structures of interest were identified for both midsagittal (10 images) and axial (34 images) views. For the midsaggetal view, the pubic symphysis, levator ani, vagina, and certix were all identified. For the axial view, the urethra, vagina, rectum, and area of the levator hiatus were determined. After structures of interest were indentified, measurements were taken. For each image, all measurements were taken three times to assess for repeatabilty. For the midsagittal view, a coordinate axis was established. After identifying the pubic symphysis, a line was marked at the outer most portion of the ultrasound where the pubic symphysis border was located. The midpoint of the line was determined. The x-axis was established from this midpoint to the most anterior part of the levator ani. The y-axis was established at the posterior border of the pubic symphysis, perpendicular to the x-axis. Once the coordinate system was in place, three angles of interest could be determined. Angle 1 was a measurement of the angle the upper portion of vagina made with the x- axis. Angle 2 was a measurement of the angle the vagina made below the x-axis to an area where a second vaginal angle can be seen. Angle 3 was classified starting from the base of Angle 2, taking a measure of a second angle of the vagina, ending at the certvix (Figure 1).