Intrapartum Ultrasound Assessment of Fetal Spine Position
Table 4
Estimation of the sensitivity, specificity, positive and negative predictive values (PPV and NPV), positive and negative likelihood ratios (LR+ and LR−), and their 95% CIs for the occiput and spinal position in the first and second stages of labour in predicting occiput posterior position at birth.
Occiput posterior position (first stage of labour)
Spine posterior position (first stage of labour)
Value
95% CI
Sensitivity
0.937
0.904–0.970
1
0.923–1
Specificity
0.552
0.484–0.620
0.979
0.959–0.998
PPV
0.147
0.099–0.195
0.8
0.746–0.854
NPV
0.99
0.976–1
1
0.967–1
LR+
2.09
41.7
LR−
0.11
0
Occiput posterior position (second stage of labour)
Spine posterior position (second stage of labour)
Value
95% CI
Value
95% CI
Sensitivity
0.875
0.830–0.920
0.937
0.904–0.970
Specificity
0.865
0.818–0.911
1
0.954–1
PPV
0.35
0.285–0.414
1
0.971–1
NPV
0.988
0.973–1
0.994
0.983–1
LR+
6.48
Infinity
LR−
0.14
0.06
95% CI estimated by the Wilson method and by the binomial exact test, when necessary.
