Table 1. Potential risk factors for failed mid-cavity vacuum-assisted delivery (VAD) and maternal and neonatal outcomes according to the VAD outcome Table 1. Potential risk factors for failed mid-cavity vacuum-assisted delivery (VAD) and maternal and neonatal outcomes according to the VAD outcome Table 1. Potential risk factors for failed mid-cavity vacuum-assisted delivery (VAD) and maternal and neonatal outcomes according to the VAD outcome Table 1. Potential risk factors for failed mid-cavity vacuum-assisted delivery (VAD) and maternal and neonatal outcomes according to the VAD outcome Table 1. Potential risk factors for failed mid-cavity vacuum-assisted delivery (VAD) and maternal and neonatal outcomes according to the VAD outcome Table 1. Potential risk factors for failed mid-cavity vacuum-assisted delivery (VAD) and maternal and neonatal outcomes according to the VAD outcome
SUCCESS SUCCESS FAILURE FAILURE p value
(n = 903) (n = 903) (n = 194) (n = 194)
Potential risk factors
Maternal body mass index (kg/m²) 24.08 ± 4.70 25.14 ± 5.57 0.014
Maternal height (m) 1.643 ± 0.061 1.629 ± 0.066 0.0047
Number of previous vaginal deliveries 0.25 ± 0.68 0.28 ± 0.73 0.49
Number of previous caesarean sections 0.14 ± 0.36 0.12 ± 0.32 0.51
Fundal height (cm) 32.89 ± 1.91 33.63 ± 2.17 < 0.001
Ratio of fundal height to maternal height (m/m) 0.20 ± 0.01 0.21 ± 0.02 < 0.001
Term (weeks of gestation) 40.12 ± 1.15 40.35 ± 1.16 0.012
Duration from 5 cm to complete cervical dilation (h) 3.85 ± 2.38 4.76 ± 2.50 < 0.001
Duration at complete cervical dilation (min) 114.61 ± 74.26 99.30 ± 82.98 0.022
Duration of expulsive efforts (min) 16.41 ± 9.46 14.22 ± 9.38 0.0037
Head - perineum distance (mm) 48.97 ± 6.86 55.74 ± 10.87 < 0.001
Fetal head position < 0.001
- occiput-anterior 369 (40.86 %) 54 (27.84 %)
- occiput-posterior or occiput-transverse 534 (59.14 %) 140 (72.16 %)
Caput succedaneum < 0.001
- absent or insignificant 839 (92.91 %) 166 (85.56 %)
- medium-sized 43 (4.76 %) 14 (7.22 %)
- bulky 21 (2.33 %) 14 (7.22 %)
Onset of labour 0.017
- spontaneous 700 (77.61 %) 135 (69.59 %)
- induced 202 (22.39 %) 59 (30.41 %)
Indication of vacuum-assisted delivery 0.35
- fetal distress 410 (45.40 %) 81 (41.75 %)
- dystocia/other 493 (54.60 %) 113 (58.25 %)
Maternal and neonatal outcomes
Apgar score at 5 minutes 9.63 ± 0.96 9.56 ± 0.93 0.34
Arterial umbilical cord blood pH 7.18 ± 0.10 7.13 ± 0.10 < 0.001
Quantity of blood loss (cc) 206.77 ± 234.43 475.23 ± 422.68 < 0.001
Perineal tear
- absent or not severe (first or second degree) 886 (98.12 %)
- severe (third or fourth degree) 17 (1.88 %)
Immediate neonatal resuscitation 0.025
- unnecessary 680 (75.30 %) 131 (67.53 %)
- yes 223 (24.70 %) 63 (32.47 %)
Neonatal transfer < 0.001
- no 857 (94.91 %) 169 (88.48 %)
- in neonatal unit or neonatal intensive care unit 46 (5.09 %) 22 (11.52 %)
Results of quantitative variables: mean ± standard deviation. Results of qualitative variables: frequency (percent). Results of quantitative variables: mean ± standard deviation. Results of qualitative variables: frequency (percent). Results of quantitative variables: mean ± standard deviation. Results of qualitative variables: frequency (percent). Results of quantitative variables: mean ± standard deviation. Results of qualitative variables: frequency (percent). Results of quantitative variables: mean ± standard deviation. Results of qualitative variables: frequency (percent). Results of quantitative variables: mean ± standard deviation. Results of qualitative variables: frequency (percent).