Table 5. Maternal characteristics by the starting dose of oxytocin for labor augmentation in multiparas.
| Starting dose | ||||
|---|---|---|---|---|
| 1 mU/min. N=1372 | 2 mU/min. N=2612 | 4 mU/min N=3296 | p | |
| Maternal race White (%) | 66 | 40 | 71 | <.0001 |
| Black (%) | 8.5 | 29 | 4.6 | |
| Hispanic (%) | 18 | 24 | 18 | |
| Other or unknown (%) | 8.1 | 6.1 | 6.7 | |
| Insurance Private (%) | 70 | 48 | 66 | <.0001 |
| Public (%) | 30 | 52 | 34 | |
| Maternal age (mean ± SD, year) | 29.0 (5.0) | 27.1 (5.4) | 28.2 (4.8) | <.0001 |
| Epidural analgesia use (%) | 87 | 79 | 93 | <.0001 |
| Intrauterine pressure catheter use (%) | 23 | 13 | 19 | <.0001 |
| Fetal scalp electrode use (%) | 32 | 25 | 25 | <.0001 |
| Cervical dilation at admission (mean ± SD, cm) | 3.3 (1.4) | 3.8 (1.5) | 3.4 (1.5) | <.0001 |
| No. of contractions/10 minutes at admission (mean ± SD) | 3.1 (1.3) | 2.7 (1.5) | 3.6 (1.3) | <.0001 |
| Effacement at admission (mean ± SD, %) | 74 (15) | 69 (19) | 75 (13) | <.0001 |
| Station at admission (median, 10th, 90th centiles) | -2 (-3, -1) | -2 (-3, -1) | -2 (-3, -1) | <.0001 |
| Cervical dilation at start of oxytocin | 4 (2, 7) | 4.5 (2.5, 8) | 4 (2, 7) | <.0001 |
| Max dose of oxytocin (mU/min) (median, 10th, 90th centiles) | 7 (1, 16) | 8 (2, 20) | 10.5 (4, 20) | <.0001 |
*
Chi-square test for categorical variables; analysis of variance for continuous variables with a normal distribution; Kruskal-Wallis test for continuous variables with a non-normal distribution.