Table 1.
Analysis of relevant factors affecting the success of VBAC.
| Factors | VBAC (n = 527) | VBNC (n = 211) | |
|---|---|---|---|
| Age/years | 31.55 ± 3.86 | 31.36 ± 4.56 | |
| Antenatal BMI/(kg/m2) | 18.5~25 | 248 (47.06) | 101 (47.87) |
| 26~30 | 22 (4.24) | 5 (2.37) | |
| > 30 | 257 (48.76) | 105 (49.76) | |
| Fetal abdominal circumference/mm | 31~34 | 375 (71.16)∗ | 68 (32.23) |
| 35~36 | 152 (28.84)∗ | 143 (67.77) | |
| Biparietal diameter of fetus/cm | 87~94 | 457 (86.72)∗ | 126 (59.72) |
| 95~97 | 98 (13.28)∗ | 85 (40.28) | |
| Palace height/cm | 32~34 | 492 (93.36)∗ | 89 (42.18) |
| 35~38 | 35 (6.64)∗ | 122 (57.82) | |
| Premature rupture of membranes | Yes | 339 (64.32)∗ | 42 (19.91) |
| No | 188 (35.68)∗ | 169 (80.09) | |
| Bishop scores | < 6 | 98 (13.28)∗ | 181 (59.72) |
| ≥ 6 | 492 (93.36)∗ | 85 (40.28) | |
| Tire head orientation | Occipital anterior position | 353 (66.97)∗ | 53 (25.12) |
| Occipital transverse position | 116 (22.02)∗ | 53 (25.12) | |
| Occipital posterior position | 58 (11.01)∗ | 105 (49.76) | |
| Thickness of lower uterine segment/cm | 3.20 ± 0.45 | 3.16 ± 0.42 | |
| Epidural anesthesia during labor | Yes | 486 (92.22)∗ | 64 (30.33) |
| No | 41 (7.78)∗ | 147 (69.67) |
Note: ∗P < 0.05, compared with the VBNC group.