Table 2. Delivery outcome.
| Dilator n = 4650 | balloon<40 n = 4103 | p | balloon≧40 n = 6616 | p | overlapping n = 1994 | p | ||
|---|---|---|---|---|---|---|---|---|
| vaginal delivery | Frequency | 3467 (74.6%) | 2967 (72.3%) | - | 4883 (73.8%) | - | 1269 (63.6%) | - |
| AOR*1 (95% C.I) | 1 | 0.91 (0.83–1.01) | 0.07 | 1.01(0.93–1.11) | 0.41 | 0.63 (0.56–0.71) | <0.01 | |
| vaginal instrumental delivery | Frequency(%) | 725 (15.4%) | 723 (17.4%) | - | 1164 (17.6%) | - | 339 (17.0%) | - |
| AOR*1 (95% C.I) | 1 | 1.20 (1.07–1.34) | <0.01 | 1.24 (1.12–1.38) | <0.01 | 1.17 (1.02–1.35) | 0.03 | |
| intrapartum hemorrhage | mean±SD (g) | 573±469 | 628±454 | - | 604±441 | - | 678±630 | - |
|
β*2 (95% C.I) |
1 | 46 (27–66) | <0.01 | 22 (5–40) | 0.01 | 91 (67–115) | <0.01 | |
| Postpartum hemorrhage | frequency(%) | 1527 (32.8%) | 1591 (38.8%) | - | 2446 (37.0%) | - | 766 (38.4%) | - |
| AOR*1 (95% C.I) | 1 | 1.25 (1.14–1.37) | <0.01 | 1.16 (1.01–1.26) | <0.01 | 1.23 (1.10–1.37) | <0.01 | |
| uterine rupture | frequency(%) | 2 (<0.1%) | 1 (<0.1%) | - | 1 (<0.1%) | - | 1 (<0.1%) | - |
| AOR*1 (95% C.I) | 1 | 0.56 (0.05–6.25) | 0.64 | 0.31 (0.03–3.57) | 0.35 | 1.08 (0.10–11.94) | 0.95 | |
| intrauterine infection | frequency(%) | 61 (1.3%) | 48 (1.2%) | - | 104 (1.6%) | - | 55 (2.8%) | - |
| AOR*1 (95% C.I) | 1 | 0.83 (0.56–1.21) | 0.32 | 1.08 (0.79–1.49) | 0.63 | 1.93 (1.33–2.79) | <0.01 | |
| Umbilical artery pH <7.1 | frequency(%) | 56 (1.3) | 49 (1.3%) | - | 116 (1.9%) | - | 30 (1.6%) | - |
| AOR*1 (95% C.I) | 1 | 0.99 (0.67–1.46) | 0.92 | 1.46 (1.06–2.02) | 0.02 | 1.21 (0.78–1.90) | 0.40 | |
| Apgar score at 5min < 7 | frequency(%) | 45 (1.0%) | 56 (1.4%) | - | 92 (1.4%) | - | 29 (1.5%) | - |
| AOR*1 (95% C.I) | 1 | 1.49 (1.00–2.21) | <0.05 | 1.49 (1.04–2.15) | 0.03 | 1.50 (0.94–2.40) | 0.09 | |
| neonatal death | frequency(%) | 13 (0.3%) | 21 (0.5%) | 32 (0.5%) | - | 14 (0.7%) | - | |
| AOR*1 (95% C.I) | 1 | 1.99 (0.99–3.99) | 0.05 | 1.87 (0.97–3.58) | 0.06 | 2.42 (1.13–5.20) | 0.02 | |
| umbilical cord prolapse | frequency(%) | 0 | 2 (<0.1%) | - | 3 (0.1%) | - | 1 (0.1%) | - |
*1 Adjusted odds ratio adjusted for maternal age at delivery, maternal height at delivery, maternal weight at delivery, baby’s weight, and baby’s sex. Values in parentheses are 95% confidence interval.
*2 β = regression coefficient adjusted for maternal age at delivery, maternal height at delivery, maternal weight at delivery, baby’s weight, and baby’s sex. Values in parentheses are 95% confidence interval.