Table 4.
Ultrasound parameters of the nulliparous and primiparous groups.
| Parameters | Nulliparous group (n = 292) | Primiparous group (n = 430) | Total (n = 722) | P | Cohen’s d |
|---|---|---|---|---|---|
| Bladder neck position at rest (mm) | 30.35 ± 3.32 | 28.48 ± 3.46 | 29.24 ± 3.52 | <0.001 | 0.55 |
| Retrovesical angles at rest (degree) | 116.39 ± 16.90 | 118.97 ± 18.28 | 117.93 ± 17.77 | 0.096 | 0.15 |
| Bladder neck position on Valsalva (mm) | 13.00 ± 8.19 | 9.84 ± 6.70 | 11.12 ± 7.49 | <0.001 | 0.43 |
| Bladder neck descent (mm) | 16.55 ± 7.75 | 18.64 ± 6.71 | 17.82 ± 7.20 | <0.001 | 0.29 |
| Retrovesical angles on Valsalva (degree) | 132.19 ± 23.19 | 136.33 ± 24.94 | 134.65 ± 24.32 | 0.005 | 0.17 |
| Urethral rotation (degree) | 37.19 ± 20.61 | 39.31 ± 18.57 | 38.45 ± 19.43 | 0.111 | 0.11 |
| Levator hiatus area on Valsalva (cm2) | 18.09 ± 6.24 | 19.14 ± 5.08 | 18.72 ± 5.60 | <0.001 | 0.19 |
| Urethral inclination angle at rest (degree) | 20.10 (15.40–26.90) | 17.85 (12.98–28.73) | 19.15 (13.90–27.73) | 0.089 | 0.03 |
| Urethral inclination angle (degree) | 14.85 (0–30.65) | 17.90 (5.68–32) | 16.55 (0–31.50) | 0.086 | 0.13 |
| Funneling of the proximal urethra | 0.011 | 0.10a | |||
| No | 279 (95.55) | 389 (90.47) | 668 (92.52) | ||
| Yes | 13 (4.45) | 41 (9.53) | 54 (7.48) |
Values shown are mean ± standard deviation, median (range), or n (%). For continuous data with a normal distribution, the Student’s independent t-test was used. For data with a non-normal distribution, the Mann–Whitney U test was used.
aThe effect size of the chi-square test was measured by Cramer’s V.