Digital Examination vs. 4D Transperineal Ultrasound-Do They Compare in Labour Management? A Pilot Study

The aim was to compare transperineal ultrasound (TPU) with parameters of the Bishop Score during the first stage of labour and evaluate how TPU can contribute towards improving labour management. Digital examination (DE) and TPU were performed on 42 women presenting at the labour ward with regular contractions. TPU measurements included the head-symphysis distance, angle of progression, diameter of the cervical wall, cervical dilation (CD) and cervical length (CL). To examine if TPU can monitor labour progress, correlations of TPU parameters were calculated. Agreement of DE and TPU was examined for CL and CD measurements and for two groups divided into latent (CD < 5 cm) and active stages of labour (CD ≥ 5 cm). TPU parameters indicated a moderate negative correlation of CD and CL (Pearson: r = -0.667; Spearman = -0.611). The other parameters showed a weak to moderate correlation. DE and TPU measurements for CD showed better agreement during the latent stage than during the active stage. The results of the present study add to the growing evidence that TPU may contribute towards an improved labour management, suggesting a combined approach of TPU and DE to monitor the latent first stage of labour and using only DE during the active stage of labour.