Table 1.
Demographic and obstetric characteristics of the study population.
| Characteristics | Responders n = 511 |
Nonresponders n = 265 |
p value |
|---|---|---|---|
| Maternal factors | |||
| Maternal age (years), mean | 30.3 (± 4.5) | 28.6 (± 5.0) | < 0.001 |
| Body mass index (kg/m2), mean | 25.0 (± 4.6) | 24.7 (± 4.2) | 0.323 |
| Smoking | 2 (0.4) | 4 (1.5) | na |
| Fetal factors | |||
| Birthweight (g), mean | 3459 (± 564) | 3426 (± 528) | 0.428 |
| Head circumference (cm), mean | 34.8 (± 2.3) | 34.7 (± 1.5) | 0.309 |
| pH umbilical artery, mean | 7.27 (± 0.08) | 7.26 (± 0.08) | na |
| Presentation | |||
| Occiput anterior | 448 (87.7) | 235 (88.7) | 0.682 |
| Occiput posterior | 26 (5.1) | 9 (3.4) | 0.282 |
| Breech, n | 19 (3.7) | 10 (3.8) | na |
| Obstetric factors | |||
| Labor onset | |||
| Spontaneous | 390 (76.3) | 197 (74.3) | 0.542 |
| Induction | 95 (18.6) | 56 (21.1) | 0.396 |
| Elective cesarean | 26 (5.1) | 12 (4.5) | 0.732 |
| Labor outcomes | |||
| Length of active secondary state (min) | 32 | 32 | na |
| Oxytocin | 325 (63.6) | 181 (68.3) | 0.217 |
| Epidural | 304 (59.5) | 187 (70.6) | 0.002 |
| Vacuum extraction | 61 (11.9) | 15 (5.7) | 0.005 |
| Episiotomy | 101 (19.8) | 47 (17.7) | 0.495 |
| Cesarean section | 69 (13.5) | 43 (16.2) | 0.306 |
| Perineal trauma | |||
| No/1st-degree injury | 216 (42.3) | 117 (44.2) | 0.616 |
| 2nd-degree injury, n | 201 (39.3) | 97 (36.6) | 0.458 |
| 3rd-/4th-degree injury | 25 (5.0) | 8 (3.1) | 0.22 |
Data are presented as the mean ± standard deviation (SD) or n (%).
* na = not analyzed.