And please welcome to the stage Dr. Joan Blomquist, the winner of the Best Epidemiological Abstract, who will present her study, Pelvic Flow Muscle Strength and the Incidence of Pelvic Flow Disorders After Vaginal and Caesarean Childbirth. All right, thank you. We'd like to thank the scientific committee for the opportunity to present our study and for the NIH for support of our work. So pelvic floor disorders are associated with childbirth and are more common 5 to 10 years after a vaginal delivery than after a C-section. As we presented at this meeting last year, the cumulative incidence of SUI, OAB, and prolapse are also higher after a vaginal delivery than after a C-section. We also know that vaginal delivery is associated with weaker pelvic floor muscle strength. For example, the peak pelvic muscle strength as measured by a perineometer is significantly lower among women who've had at least one vaginal delivery than among women who've delivered all their children by C-section. Prior work by our group has shown that weak pelvic floor muscles, along with other factors, such as hiatal strength, account for at least part of the relationship between vaginal delivery and prolapse. As pelvic floor muscle training is a recommended treatment option for pelvic floor disorders, it's possible that weak pelvic floor muscle strength is actually a modifiable risk factor for pelvic floor disorders. As such, it's important for us to understand how pelvic floor muscle strength affects the course and progression of pelvic floor disorders over time. Therefore, the objectives of our study were to investigate the association between pelvic floor muscle strength and the incidence of PFDs, and to determine which maternal and obstetric characteristics, if any, modify the association. This study is one of the primary aims of the Mother's Outcome After Delivery Study, which is a prospective cohort study of Paris women. Participants were recruited five to 10 years after their first delivery, and were followed annually for up to nine years. At each annual visit, they completed questionnaires, including the EPIC, and had a physical exam, including the POPQ exam. For this study, our primary exposure of interest was pelvic floor muscle strength, which we measured with a Paratron perineometer. Previous studies have shown that the Paratron is reproducible and reliable. We measured the average peak pelvic muscle strength on the second annual visit, which on average was 7.7 years from their first delivery, and then we divided participants into two groups based on their pelvic muscle strength. Those with a peak pressure of less than 20 centimeters of water, and those with a peak pressure of greater than or equal to 20 centimeters. Additional covariates included delivery mode, race, parity, age at first delivery, BMI, and the size of the genital hiatus. Our primary outcomes were the four PFDs. Participants were considered to have SUI, OAB, or AI if their EPIC scores were above the previously validated threshold scores, or if they reported prior treatment for that disorder. Pelvic organ prolapse was defined as prolapse beyond the hymen on POPQ, or a report of surgery for prolapse. Of the 1,528 mode participants, 1,143 had a Paratron measurement and completed at least two visits, and therefore were included in this analysis. This included 555 participants who delivered all their children by C-section, and 588 who had at least one vaginal delivery. Here you see the demographics at enrollment based on pelvic muscle strength. As expected, participants who had a vaginal delivery had weaker pelvic floor muscle strength. There was a trend towards a higher BMI in the weaker muscle strength group, and there was a larger genital hiatus in the weaker pelvic muscle group. There was no difference between groups with regards to age at first delivery, race, or parity. The number of follow-up visits was equivalent between the groups, making comparison over time feasible. So for our first objective, to describe the cumulative instance of each PFD, we considered first delivery as the time of origin. So for this analysis, we included participants who had the disorder at study entry, as well as those who developed the disorder during the follow-up. We used conventional log-normal models to estimate cumulative instance, and we stratified this analysis by delivery mode. So here you see the cumulative instance for each of the four PFDs over time. In each figure, the blue lines represent the vaginal delivery group, and the red lines represent the cesarean group. The solid lines are those with a peak pressure of less than 20, and the dashed lines are those with a peak pressure of greater than or equal to 20. Within the vaginal delivery group, a peak pressure of less than 20 was associated with a higher cumulative instance of SUI, OAB, and prolapse. TR here stands for time ratio. A time ratio of .67 implies that the time to develop SUI for women with weak muscles is approximately 67% of the time that it would take to develop SUI for women with stronger muscles. Also notice that for the cesarean group, represented by the red lines here, that the instance of each of the four PFDs was similar between the two pelvic muscle strength groups. For our second aim, to determine which maternal and obstetrical characteristics modify the association between pelvic muscle strength and pelvic floor disorders, we excluded participants who already had the disorder at study entry because they could not provide prospective data for us to model hazard. Therefore, we considered five years from first delivery as the time of origin. We used staggered entry methods to deal with the fact that they could have entered the study anywhere between five and 10 years after their first delivery, and we used classical semi-parametric proportional hazard models. Again, we stratified this analysis by delivery mode. Within the vaginal delivery group, a peak pressure of less than 20 was associated with a higher hazard to develop prolapse, but not SUI, OAB, or AI. Remember, we excluded the prevalent cases in this analysis, which is likely why these results look a little different than what we just saw for the cumulative incidence. In the C-section only group, there was no association between pelvic muscle strength and PFDs. Here we'll look at the multivariable analysis for the vaginal delivery group, which was adjusted for BMI and size of the genital hiatus. As you can see, the association between pelvic muscle strength and prolapse is now attenuated and no longer statistically significant. There was no association between BMI and PFDs in this group. And a larger genital hiatus was associated with a higher hazard of prolapse. In the C-section group, there was no association between pelvic muscle strength and PFDs. Obesity was associated with a higher hazard of SUI, AI, and AI. And a larger genital hiatus was associated with a higher hazard of prolapse. The strengths of our study are its longitudinal design. We used validated tools to measure each of the PFDs. Their size of our study was large enough and the duration of follow-up was long enough to model differences between groups, and we used time-varying measures. We do have several limitations. Although we had up to nine years of follow-up, this is not long enough to study the association of pelvic muscle strength and incidence of PFDs later in life. Due to the design of the study, we measured pelvic muscle strength several years after first delivery. Ideally, strength would have been measured shortly after delivery to better demonstrate a temporal relationship with the development of PFDs. We also considered pelvic muscle strength to be a constant over time, and our focus studied on peak pelvic muscle strength, which is really only one aspect of pelvic muscle function. So in conclusion, pelvic muscle strength is associated with the cumulative incidence of SUI, OAB, and prolapse among women with at least one voucher delivery, but not among women who delivered by cesarean only. And this association is attenuated when controlling for BMI and genital hiatus. This analysis allows us to identify a group of high-risk women who may benefit from pelvic floor physical therapy as a prevention method. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. And that forceps delivery in particular is associated with weaker pelvic muscle strength and a higher risk of developing PFTs. And what about cesarean sections? Do you have emergency and elective cesarean sections? For the C-section, so within the C-section group, it includes participants who had C-section without labor, those who got to full dilation, and those who pushed. And we, in our previous work, we've shown that in those three groups, there's no difference in pelvic muscle strength. And in addition, there's no difference in PFTs. And so that's why we consider them all as one group. Again. Thank you. Yeah, I wanted to ask a quick question. How did you pick a peak pressure of 20 as your cut point? So we picked a peak pressure of, there's really nothing out there in the literature as to what would be considered strong and what's weak. We did it based on tertiles of our population. So a third of our participants had a peak pressure of less than 20. And did you look at it, do any kind of sensitivity analysis to see if maybe a peak pressure of 10 was more, or if you picked a peak pressure of 30, if there was any differences? Yeah, this was the good cutoff based on those. I have, I'm sorry, I have two or three questions. One is, we are not familiar with the perineum meter, and we would like to know what a perineum meter is. And could there be a user difference between person to person when they use the perineum meter? Does it replace the Oxford scale in the measurement of the pelvic muscle strength? Second thing is, did you stratify your patients according to their race, or that was not entered at all? And looking at your data, it looks like maybe having a C-section, we can avoid all the problems. Thank you. Okay, so the first question was on the Peritron Perineometry. It's a compressible device that has a handheld microprocessor with it, and you place it into the vagina and zero it, and then ask the patient to squeeze, which is how you get the pressure. And it's been used in a number of different studies, and has been shown to have a very good correlation with the Oxford scale, and to be reliable and reproducible between different people using it. And we actually did tests within our researchers who were doing it. The second question. Race. So we looked at race, and there was not a difference between groups, which is why we didn't stratify this analysis for it. Sorry, we don't have time for any further questions, but I'm sure you'll answer some during the coffee break, Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you. Thank you.

pelvic floor muscle strength

pelvic floor disorders

vaginal deliveries

caesarean deliveries

perineometer