W. Thomas Gregory MD, Abstract Co-Author: Nothing to Disclose

Terri Elizabeth Reichner MD, Abstract Co-Author: Nothing to Disclose

Amanda Holland BS, Abstract Co-Author: Nothing to Disclose

Amy Suzanne Thurmond MD, Presenter: Royalties, Cook Group Incorporated Stockholder, Conceptus Inc

Pelvic organ prolapse is linked to parity, and for millennia has resulted in stress urinary incontinence and other symptoms which affect large numbers of women and limit their ability to work and socialize. We used MRI to evaluate changes in the pelvic floor before and after a first pregnancy. We compared these changes between those undergoing cesarean delivery and those having a vaginal delivery.

This is a subgroup from an ongoing prospective cohort study of nulliparous women planning pregnancy. Participants have a standardized evaluation before pregnancy (Visit 1), 6 weeks after delivery (Visit 2), and then 6 months after delivery (Visit 3). At all three visits the participant has an interview with questionnaire, clinical pelvic exam, transperineal and endoanal 3D ultrasound, electromyography (EMG) of the pelvic floor and anal sphincter muscles, and pelvic MRI using a 3 Tesla magnet. This report focuses on MRI findings of the women who have completed Visits 1 and 2.

In 42 women, there was no significant change in bony measurements before and after pregnancy and delivery. There were however significant differences in the soft tissue measurements, including statistically significant inferior position of the bladder neck 6 weeks after delivery in all women, which was related to descent of the puborectalis muscle. This was more pronounced following vaginal delivery (31 women) compared to cesarean delivery (15 women). This was particularly evident during the dynamic maneuvers of kegel and valsalva. Interestingly, the pre-pregnancy values of bladder neck descent were larger in the women who ended up needing cesarean delivery.

Our data supports observations that after a first pregnancy women who had a vaginal delivery are 5 to 6 times more likely to have measurable pelvic prolapse then women who had cesarean delivery. Universal cesarean delivery to avoid future pelvic prolapse would not however be safe or cost effective. The comparison of pelvic structures in the same woman before and after delivery has not been done before, and may help us predict the women in whom the benefits of cesarean delivery for maintaining pelvic support, outweigh the risks.

This is the first large study to image the pelvic floor anatomy in women before and after their first delivery of a child.

Gregory, W, Reichner, T, Holland, A, Thurmond, A, Comparison of the Pelvic Floor before Pregnancy and 6 Weeks after Delivery: An MRI Study.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13015636.html