Relationship between urethral motion profile and parity assessed by translabial ultrasound imaging

PURPOSE: This study aims to describe the differences in the urethral motion profile (UMP) of primiparous and multiparous women immediately postpartum. METHODS: This prospective study recruited 65 women (29 primiparous, 36 multiparous) one–seven days postpartum. The patients underwent a standardised interview and two-dimensional translabial ultrasound (TLUS). To evaluate the UMP, the urethra was manually traced and divided into five segments with six equidistant points. The mobility vector (MV) for each point was calculated as [Formula: see text] . A Shapiro–Wilk test was conducted to test normality. An independent t-test and a Mann–Whitney test were conducted to express differences between the groups. The Pearson correlation coefficient was used to determine the relationships among MVs, parity and confounders. Finally, a univariate generalised linear regression analysis was performed. RESULTS: MV1–MV4 were found to be normally distributed. A significant difference for all MVs, except for MV5, was demonstrated between parity groups (MV1: t = 3.88 (p < .001), MV2: t = 3.82 (p < .001), MV3: t = 2.65 (p = .012), MV4: t = 2.54 (p = .015), MV6: U = 150.00 (exact sig. two tailed = .012)). A strong-to-very strong mutual correlation was observed between MV1 to MV4. The univariate generalised linear regression showed that parity can predict up to 26% of urethral mobility. CONCLUSION: This study shows that multiparous women have significantly higher urethral mobility compared to primiparous women in the first week postpartum, with the most significant effect observed in the proximal urethra.