Cesarean delivery may offer long-term pelvic floor support

Women who underwent cesarean delivery may have lower chances of pelvic organ prolapse and stress urinary incontinence surgeries, according to a register-based linkage study published in the American Journal of Obstetrics & Gynecology.

Further, vaginal births increased the cumulative absolute risk for both surgeries, according to the study.

“The long-term effect of one or more cesarean deliveries on the risk of reconstructive urogenital surgery, representing the effect of one or more pregnancies, was similar to that in nulliparous women who are unaffected by childbirth,” Jennie Larsudd-Kåverud, MD, of the department of obstetrics and gynecology at Södra Älvsborgs Hospital in Borås, Sweden, and colleagues wrote. “This is crucial information for health care economic calculations and women’s autonomous decision regarding their preferred mode of delivery.”

However, it is important to note that cesarean delivery confers risks to both the mother and child, and that ACOG does not recommend elective cesarean deliveries before 39 weeks’ gestation unless otherwise indicated.

Defining the study population

Larsudd-Kåverud and colleagues examined data from three nationwide registers — the Swedish National Quality Register of Gynecological Surgery, the Swedish Medical Birth Register and the Total Population Register — to observe how vaginal births, cesarean deliveries, parity and factors unrelated to childbirth in nulliparous women affect the risk for reconstructive urogenital surgery in women aged 45 years or older.

Participants were stratified into the following groups:

• nulliparous;
• having had one or more vaginal deliveries; and
• having had one or more cesarean deliveries.

The Total Population Register included 2,309,765 women born in 1960 and was used as a reference group to calculate risk for each group.

The present study included 20,488 women who experienced stress urinary incontinence (SUI) surgery and 39,617 who went through pelvic organ prolapse (POP) surgery between 2010 and 2017. Of these, 690 women had concomitant procedures, leaving 59,415 women for analyses.

In total, 1,610 women were nulliparous, 57,131 had at least one vaginal delivery and 674 had at least one cesarean delivery. Women who delivered vaginally were overrepresented for POP surgery (RR = 1.23; 95% CI, 1.22-1.24) and SUI surgery (RR = 1.17; 95% CI, 1.15-1.19) compared with women aged 45 years and older in the general population (n = 1,837,883), while nulliparous women (POP: RR = 0.14; 95% CI, 0.13-0.15; and SUI: RR = 0.31; 95% CI, 0.29-0.33) and women who delivered by cesarean section (POP: RR = 0.055; 95% CI, 0.046-0.065; and SUI: RR = 0.4; 95% CI, 0.36-0.43) were underrepresented in both surgeries.

Risk for POP, SUI surgery

Researchers found that the lowest absolute risk (AR) of POP surgery was after cesarean delivery (AR = 0.09 per 1,000 women; 95% CI, 0.08-0.11). Compared with women who underwent vaginal delivery, the risk for this surgery differed by a factor of 23 (AR = 2.11 per 1,000 women; 95% CI, 2.09-2.13).

Compared with women who were nulliparous, there was a steady and pronounced increase in the absolute risk for POP surgery after four or more vaginal births (nulliparous group, AR = 2.3 per 1,000 women; 95% CI, 2.2-2.5; vs. vaginal delivery group, AR = 38.7 per 1,000 women; 95% CI, 37.8-39.8). This was not found after cesarean delivery.

Additionally, the first vaginal delivery had the largest absolute risk increases for both POP and SUI surgery, at sixfold and threefold, respectively. However, the second vaginal birth had the lowest absolute risk increases of POP and SUI surgery, at about one-third and one-tenth of the absolute risk for the first vaginal delivery, respectively.

The risk for both POP and SUI surgery in the cesarean delivery group was insignificant and comparable with that of nulliparous women.

Since the risk found for the cesarean delivery method was similar to the risk found for nulliparous women, researchers concluded that it may provide protection later in life from POP and SUI surgery.

“We found no evidence based on the results of this study that pregnancy alone, or the additive effect of multiple pregnancies, increased the risk of surgery for POP nor UI, over and above that in nulliparous women,” Larsudd-Kåverud and colleagues wrote. “Giving birth exclusively by cesarean delivery seemed to maintain the nulliparous state of the pelvic floor support in the long-term. Therefore, health care resources used for urogenital surgery could be contributed to the negative consequences of vaginal delivery. Yet, this is only one part of women’s total reproductive burden.”

Reference:

• ACOG. Cesarean Delivery on Maternal Request. https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2019/01/cesarean-delivery-on-maternal-request. Published Dec. 20, 2018. Accessed Aug. 11, 2022.