Table 2. Determinants of failed mid-cavity vacuum-assisted delivery in bivariate and multivariate analyses. Table 2. Determinants of failed mid-cavity vacuum-assisted delivery in bivariate and multivariate analyses. Table 2. Determinants of failed mid-cavity vacuum-assisted delivery in bivariate and multivariate analyses. Table 2. Determinants of failed mid-cavity vacuum-assisted delivery in bivariate and multivariate analyses. Table 2. Determinants of failed mid-cavity vacuum-assisted delivery in bivariate and multivariate analyses. Table 2. Determinants of failed mid-cavity vacuum-assisted delivery in bivariate and multivariate analyses.
Bivariate analysis Bivariate analysis Multivariate analysis Multivariate analysis Multivariate analysis
OR [95 % CI] p - value OR [95 % CI] p - value p - value
Maternal body mass index (kg/m²) 0.11
< 25 1
≥ 25 1.29 [0.94 - 1.77]
Maternal body mass index (kg/m²) 0.017
< 30 1
≥ 30 1.66 [1.10 - 2.51]
Maternal height (m) 0.0038 < 0.001 < 0.001
≤ 1.54 2.61 [1.47 - 4.62] 2.92 [1.56 - 5.49]
1.55 – 1.64 0.98 [0.70 - 1.37] 0.82 [0.57 - 1.20]
1.65 – 1.74 1 1
≥ 1.75 0.69 [0.30 - 1.59] 0.61 [0.25 - 1.51]
Number of previous vaginal deliveries 0.51
0 1
1 0.92 [0.57 - 1.49]
≥ 2 1.45 [0.74 - 2.82]
Number of previous caesarean sections 0.65
0 1
≥ 1 0.90 [0.56 - 1.44]
Fundal height (cm) < 0.001
≤ 33 1
> 33 1.81 [1.32 - 2.48]
Ratio of fundal height to maternal height (m/m) < 0.001
≤ 0.20 1
> 0.20 2.05 [1.49 - 2.83]
Term (weeks of gestation) 0.039
< 41 1
≥ 41 1.40 [1.02 - 1.93]
Term (weeks of gestation) 0.0050 0.032 0.032
< 42 1 1
≥ 42 2.16 [1.26 - 3.70] 1.96 [1.06 - 3.62]
Duration from 5 cm to complete cervical dilation (h) 0.013 0.0091 0.0091
< 3 1 1
≥ 3 1.60 [1.11 - 2.32] 1.72 [1.15 - 2.59]
Duration at complete cervical dilation (min) 0.046
0 - 60 1
61 - 120 0.55 [0.32 - 0.92]
121 - 180 0.63 [0.42 - 0.94]
≥ 181 0.71 [0.46 - 1.11]
Duration of expulsive efforts (min) 0.0012 0.0013 0.0013
0 - 10 1 1
11 - 20 1.07 [0.74 - 1.54] 1.27 [0.84 - 1.93]
21 - 30 0.49 [0.32 - 0.74] 0.52 [0.32 - 0.84]
≥ 31 0.91 [0.39 - 2.17] 1.30 [0.51 - 3.33]
Head - perineum distance (mm) < 0.001 < 0.001 < 0.001
40 - 50 1 1
51 - 60 1.58 [1.10 - 2.27] 1.60 [1.08 - 2.36]
≥ 61 7.73 [4.76 - 12.56] 6.66 [3.82 - 11.64]
Fetal head position < 0.001 0.041 0.041
- occiput-anterior 1 1
- occiput-posterior or occiput-transverse 1.79 [1.27 - 2.52] 1.48 [1.02 - 2.16]
Caput succedaneum 0.0012 < 0.001 < 0.001
- absent or insignificant 1 1
- medium-sized 1.65 [0.88 - 3.08] 1.68 [0.85 - 3.33]
- bulky 3.37 [1.68 - 6.76] 4.19 [1.95 - 9.03]
Onset of labour 0.018
- spontaneous 1
- induced 1.52 [1.07 - 2.14]
Indication of vacuum-assisted delivery 0.35
- dystocia/other 1
- fetal distress 1.16 [0.85 - 1.59]