Vaginal birth after cesarean linked to greater risk for pelvic floor surgery
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Among women with a previous cesarean section, those who underwent vaginal delivery instead of another cesarean delivery were more likely to need pelvic floor surgery, according to data published in PLOS Medicine.
“Cesarean section rates have increased in many parts of the world, leading to increasing numbers of pregnant women who have had a cesarean birth in the past,” Kate E. Fitzpatrick, DPhil, MSc, a senior researcher in the National Perinatal Epidemiology Unit at the University of Oxford in the United Kingdom, told Healio. “These women may be given a choice between planning another birth by cesarean or planning a vaginal birth, provided they do not have medical reasons why a vaginal birth is not advised. While clinical guidelines recommend that women should be counseled on the associated risks and benefits to help them make an informed decision about this choice, there is limited evidence about the effect of this choice on long-term outcomes including women’s future risk of experiencing pelvic floor disorders such as urinary incontinence.”
Defining the cohort
Fitzpatrick and colleagues used linked data from five Scottish national datasets to identify 47,414 singleton term births between 1983 and 1996 that occurred after at least one cesarean delivery. To evaluate for time to pelvic floor surgery, the researchers followed data for each woman from their first eligible birth until they emigrated or died, or until Dec. 31, 2016, was reached.
Of note, assessment of time to surgery was restarted with each successive birth during the follow-up period.
In total, 31,672 (66.8%) women had vaginal births and 15,742 (33.2%) women elected to have another cesarean section. The median length of follow-up was 22.1 years and the median age at end of follow-up was 51 years. In that time, 1,159 (2.44%) women underwent pelvic floor surgery, of whom 613 (1.29%) underwent surgery for pelvic organ prolapse, 531 (1.12%) underwent surgery for urinary incontinence and 128 (0.27%) underwent surgery for rectal prolapse or fecal incontinence.
Risk for pelvic floor surgery
The crude incidence rate of any pelvic floor surgery was 1.75 per 1,000 person-years (95% CI, 1.64-1.86) among women who underwent vaginal delivery and 0.66 per 1,000 person-years (95% CI, 0.57-0.75) among those who elected to have a repeated cesarean delivery. Adjusting for sociodemographics, medical factors and obstetric-related factors, women who had a vaginal birth were more likely to undergo any pelvic floor surgery (adjusted HR = 2.38; 95% CI, 2.03-2.8).
Additionally, women who chose to have a vaginal vs. cesarean delivery were more likely to have surgery for pelvic organ prolapse (aHR = 3.17; 95% CI, 2.47-4.09) or urinary incontinence (aHR = 2.26; 95% CI, 1.79-2.84).
Notably, 5,001 (15.8%) of the 31,672 women who opted to have a vaginal delivery ultimately had an in-labor nonelective cesarean section. Only women who had a successful vaginal delivery had a greater risk for pelvic floor surgery compared with those who had an elective cesarean delivery; women who had a nonelective cesarean delivery had a similar risk vs. those who had an elective cesarean delivery.
“Our findings provide new information to counsel women who have had a cesarean birth in the past about the risks and benefits associated with their future birth choices,” Fitzpatrick said. “However, it is important to mention this is not the only information these women should consider. For example, they may wish to consider how many more children they would like to have, as the likelihood of having serious complications in future pregnancies increases with each cesarean birth. Among pregnant women who have had a cesarean section in the past, planning a vaginal birth compared to planning another cesarean is also thought to be associated with other risks and benefits.”