Longitudinal study of quantitative changes in pelvic organ support among parous women

Abstract

Background: Pelvic organ prolapse is more common among parous (vs nulliparous) women and also more common after vaginal (vs cesarean) birth. However, very little is known about how childbirth affects the course and progression of the genital hiatus across a woman's life span.

Objective: The objective of the sttudy was to investigate the longitudinal, quantitative changes in pelvic organ support after childbirth, focusing on the impact of vaginal vs cesarean delivery.

Study design: This was a prospective longitudinal cohort study in which parous women were recruited 5-10 years from first delivery and followed up annually. Using data from annual pelvic organ prolapse quantification examinations, we considered changes in vaginal support at the anterior vaginal wall (point Ba), the vaginal apex (point C), and the posterior wall (point Bp). In univariate and multivariable models, we compared pelvic organ support between women who had delivered at least 1 child vaginally vs those delivered exclusively by cesarean. Other covariates considered included race, age at first delivery, and the size of the genital hiatus. For models of support at Ba and Bp, we also considered the independent association with apical support. For women who delivered vaginally, we also considered forceps birth.

Results: A total of 1224 women participated for a total of 7055 woman-visits. In multivariable models, vaginal birth was associated with significantly worse support 5 years from first delivery. Also, women with at least 1 vaginal birth had more rapid worsening of support at point C. The width of the genital hiatus was a significant independent predictor of worse support 5 years from delivery as well as the rate of change over time. In models that controlled for the genital hiatus, the strength of the impact of vaginal birth was attenuated.

Conclusion: Vaginal birth was associated with worse support 5 years from first delivery and with more rapid deterioration in support at the apex. Above and beyond the impact of vaginal birth, the size of the genital hiatus may be an independent marker for those at greatest risk of prolapse progression.

Keywords: cesarean delivery; genital hiatus; vaginal birth.

Figure 1

Distribution, among women with at least three study visits (n=1091), of the rates of change (per 5 year interval) in the position of each Pelvic Organ Prolapse Quantification point. Rates of change are shown for points Ba, C and Bp. Panels in the top row represent women with a history of only cesarean birth; panels in the lower row represent those with at least one vaginal birth. The grey bars indicate a rate of change less than zero (e.g., improvement in support). Shown in the bottom right corner of each panel is the percentage of women for whom the slope was positive (e.g., worsening in support), indicated by the black bars. Shown in the right upper corner of each panel is the median rate of change and the interquartile range.