Compartment-Specific Associations Between Perineal Body Length and Pelvic Organ Prolapse in Postpartum Women

Pelvic floor dysfunction (PFD) is common after childbirth, but the role of perineal body dimensions in compartment-specific prolapse remains unclear. To investigate the association between perineal body length and various types of pelvic floor dysfunction in postpartum women, with emphasis on compartment-specific effects.

This cross-sectional study included 182 women assessed 30-90 days postpartum at a specialized pelvic floor clinic. Trained examiners measured perineal body length; outcomes assessed were anterior/posterior wall prolapse, uterine prolapse, stress urinary incontinence (SUI), and pelvic floor muscle weakness. Multivariable logistic regression (adjusted for age, pre-pregnancy BMI, delivery mode, postpartum days) was performed. Examiners were partially blinded.

Perineal body length showed compartment-specific prolapse associations: longer length was inversely associated with posterior wall prolapse (OR 0.544, 95% CI 0.313-0.943, P = 0.030) but positively associated with anterior wall prolapse (OR 3.558, 95% CI 1.133-11.167, P = 0.030; exploratory due to a few non-cases and wide CIs). No significant associations were observed with SUI, muscle weakness, or uterine prolapse. Sensitivity analysis including 16 additional women assessed after 90 days (total n = 198) showed consistent results.

Perineal body length is differentially associated with anterior and posterior prolapse, reflecting compartment-specific pelvic floor support. The cross-sectional design and lack of pre-delivery measurements mean findings are associative (not causal) and should be validated in larger prospective studies.