Legends
Figure 1. Sonographic parameters of fetal head descent and rotation: (a)
The angle of progression (AoP) in the transperineal longitudinal plane;
(b) The head-perineum distance (HPD) measured on a sagittal scan and (c)
the midline angle in the transperineal axial plane.
Figure 2. Receiver operating characteristic curve for the prediction
model of the midline angle combined with the maternal height. The area
under the curve (AUC) for the prediction of successful fetal head
rotation was 0.667 (95% CI, 0.583-0.751; P<0.001).
Figure 3. Calibration curves for prediction models. (a) Model of fetal
occiput rotation; (b) Model of vaginal delivery.
Figure 4. Receiver operating characteristic curve of the combination of
maternal height and angle of progression (AoP) for predicting vaginal
delivery at different scan intervals. The first scan time (T1) was at
the latent labor phase (red line). Subsequent scans were performed at 3
hours intervals (T2, blue line; T3, green line). The areas under the
curves (AUCs) for the prediction model were 0.738 (95% CI, 0.763-0.793;
P<0.001) at T1, 0.820 (95% CI, 0.752-0.888;
P<0.001) at T2 and 0.940 (95% CI, 0.885-0.995;
P<0.001) at T3, respectively.
Table 1 Maternal and newborn characteristics of participants
Table 2 The angle of progression (AoP), head–perineum distance (HPD)
and midline angle (MLA) at different time points, according to the mode
of delivery
Table 3 Final logistic regression models to predict spontaneous fetal
occiput rotation and vaginal delivery