Background

The long-term effects of vaginal delivery, parity, and pregnancy on the pelvic floor remain uncertain and controversial issues. In comparison with studies using self-reported symptoms, surgical register data may offer a more valid means for evaluating the relative influence of these risk factors.

Objective

This study used data from 3 high-quality nationwide registers, namely the Swedish National Quality Register of Gynecological Surgery, the Swedish Medical Birth Register, and the Total Population Register, to evaluate the contribution of vaginal and cesarean delivery, parity, and factors not related to childbirth to the long-term risk for reconstructive urogenital surgery.

Study Design

This was a register-based linkage study among women aged ≥45 years who underwent urinary incontinence or prolapse surgery from 2010 to 2017. This surgical cohort was divided into nulliparous women, women with ≥1 cesarean deliveries only, those with ≥1 vaginal deliveries, and according to the number of births. A corresponding reference group was constructed based on women born in 1960 from the Total Population Register (n=2,309,765). The Swedish Medical Birth Register was used to determine the rate of women with cesarean and vaginal delivery and their respective parity. Absolute and relative risk were presented per 1000 women with 95% confidence intervals. Pairwise differences were analyzed with Fisher exact tests and the Mann-Whitney U test for dichotomous and continuous variables. The trend between ≥3 ordered categories of dichotomous variables was analyzed with Mantel-Haenszel statistics.

Results

A total of 39,617 women underwent prolapse surgery and 20,488 underwent incontinence surgery. Among women with prolapse surgery, 97.8% had ≥1 vaginal delivery, 0.4% had ≥1 cesarean delivery only, and 1.9% were nullipara. Corresponding figures for those with incontinence surgery were 93.1%, 2.6%, and 4.3%, respectively. Women with vaginal deliveries were overrepresented in the prolapse surgery (relative risk, 1.23; 95% confidence interval, 1.22–1.24; P<.001) and incontinence surgery groups (relative risk, 1.17; 95% confidence interval, 1.15–1.19; P<.001). Nulliparous and cesarean delivered women were underrepresented in the prolapse surgery (relative risk, 0.14; 95% confidence interval, 0.13–0.15 and relative risk 0.055; 95% confidence interval, 0.046–0.065; all P<.001) and incontinence surgery groups (relative risk, 0.31; 95% confidence interval, 0.29–0.33 and relative risk, 0.40; 95% confidence interval, 0.36–0.43). The absolute risk for prolapse surgery was lowest after cesarean delivery (0.09 per 1000 women; 95% confidence interval, 0.08–0.11) and differed by a factor of 23 (absolute risk, 2.11 per 1000 women; 95% confidence interval, 2.09–2.13) from that after vaginal birth. The absolute risk for prolapse and incontinence surgery increased consistently with parity after vaginal births. This trend was not observed after cesarean delivery, which is on par with that of nulliparous women. The first vaginal birth contributed the highest increase in the absolute risk for pelvic organ prolapse surgery (6-fold) and stress urinary incontinence surgery (3-fold). The second vaginal birth contributed the lowest increase in the absolute risk for pelvic organ prolapse surgery (∼1/3 of the first vaginal birth) and for stress urinary incontinence surgery (∼1/10 of the first vaginal birth).

Conclusion

Surgery for urinary incontinence and prolapse was almost exclusively related to vaginal parity. The risk for prolapse surgery increased consistently with parity after vaginal births but not after cesarean delivery, whereas the risk associated with cesarean delivery was on par with that of nulliparous women. Thus, cesarean delivery seems to offer protection from the need for pelvic organ prolapse and stress urinary incontinence surgery later in life.

中文翻译：

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妊娠、产次和分娩方式对尿失禁和脱垂手术的影响——一项全国注册研究

背景

阴道分娩、产次和妊娠对盆底的长期影响仍然是不确定且有争议的问题。与使用自我报告症状的研究相比，手术登记数据可能为评估这些危险因素的相对影响提供更有效的手段。

客观的

本研究使用了来自 3 个高质量全国登记处（即瑞典国家妇科手术质量登记处、瑞典医疗出生登记处和总人口登记处）的数据，以评估阴道分娩和剖宫产、产次以及不相关因素的贡献。分娩至重建泌尿生殖手术的长期风险。

学习规划

这是一项基于登记的关联研究，对象为 2010 年至 2017 年间接受过尿失禁或脱垂手术的 45 岁以上女性。该手术队列分为未产妇、仅剖宫产 1 次以上的女性、阴道分娩 1 次以上的女性、并根据出生人数。根据总人口登记册中 1960 年出生的女性（n=2,309,765）构建了相应的参考组。瑞典医学出生登记用于确定剖腹产和阴道分娩妇女的比例及其各自的胎次。以 95% 置信区间呈现每 1000 名女性的绝对风险和相对风险。使用 Fisher 精确检验和二分变量和连续变量的 Mann-Whitney U检验分析成对差异。使用Mantel-Haenszel 统计分析≥3 个有序类别的二分变量之间的趋势。

结果

共有 39,617 名女性接受了脱垂手术，20,488 名女性接受了失禁手术。在接受脱垂手术的女性中，97.8% 的女性进行过 1 次以上的阴道分娩，0.4% 的女性进行过 1 次以上的剖腹产，1.9% 的女性未产过。接受失禁手术的相应数字分别为 93.1%、2.6% 和 4.3%。阴道分娩的女性在脱垂手术组（相对风险，1.23；95% 置信区间，1.22–1.24；P <.001）和失禁手术组（相对风险，1.17；95% 置信区间，1.15–1.19；P ）中所占比例过高。 <.001)。未产妇和剖腹产妇女在脱垂手术组中的代表性不足（相对风险，0.14；95% 置信区间，0.13-0.15；相对风险 0.055；95% 置信区间，0.046-0.065；所有 P <.001）和失禁手术组（相对风险，0.31；95% 置信区间，0.29–0.33 相对风险，0.40；95% 置信区间，0.36–0.43)。剖宫产后脱垂手术的绝对风险最低（每 1000 名女性 0.09；95% 置信区间，0.08–0.11），相差 23 倍（绝对风险，每 1000 名女性 2.11；95% 置信区间，2.09–2.13） ）从阴道分娩后。脱垂和失禁手术的绝对风险随着阴道分娩后的产次而增加。剖腹产后没有观察到这种趋势，与未产妇的情况相同。首次阴道分娩导致盆腔器官脱垂手术（6 倍）和压力性尿失禁手术（3 倍）的绝对风险增加最高。第二次阴道分娩对盆腔器官脱垂手术（约第一次阴道分娩的 1/3）和压力性尿失禁手术（约第一次阴道分娩的 1/10）绝对风险的增加最低。

结论

尿失禁和脱垂手术几乎完全与阴道产次有关。阴道分娩后，脱垂手术的风险会随着产次的增加而增加，但剖腹产后则不会增加，而剖腹产的风险与未产妇的风险相当。因此，剖腹产似乎可以避免日后进行盆腔器官脱垂和压力性尿失禁手术。