Reliability and Reproducibility of Analyzing 3D Transperineal Ultrasound Volumes Obtained in the First Phase of Labor - A Pilot Study

Abstract

Purpose The aim of this study was to investigate the reliability and reproducibility of transperineal ultrasound (TPUS) in the initial phase of labor. As TPUS is a common method, it could supplement vaginal palpation and even replace it in certain situations. In addition, we used a 4-dimensional method for the assessment of cervical effacement. Materials and Methods 54 women in labor were included and underwent TPUS. The resulting images from the acquired 4D volumes were evaluated after the examination for the first time and a second time after 21 days. The measured values were cervical length, dilatation and effacement, the angle of progression (AoP), and head-perineum distance. Results 54 patients were examined. TPUS images were unable to be evaluated in 12 patients because of cervical dilatation of more than 5 cm or poor image quality. Thus, 42 measurements were included. The concordance correlation coefficients according to Lin are satisfactory overall, with one exception for cervical effacement. The accuracy component of cervical length (CCCLin: 0.93; accuracy: 1.00), dilatation (CCCLin: 0.93; accuracy: 1.00), and AoP (CCCLin: 0.87; accuracy: 1.00) is excellent and still high for the head-perineum distance (CCCLin: 0.89; accuracy: 0.96) and cervical effacement (CCCLin: 0.77; accuracy: 0.97). Conclusion TPUS is a valuable noninvasive tool with good diagnostic accuracy for the AoP, cervical length, and dilatation. Our study provides support for the use of TPUS to complement a vaginal examination. It should not replace a digital examination but should serve as a suitable alternative method for monitoring labor progression in the future.

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

“…However, it cannot be concluded that TPU measurements were more imprecise, as the actual length of the cervix is unknown. CL measured by TPU has been shown to be reproducible [10] and to be in good agreement with transvaginal measurements of CL [32]. Therefore, we conclude that despite poor agreement in our study, CL measured by TPU could still be valuable in labour management.…”

“…However, there is increasing evidence that other examination methods to monitor labour progress may be useful and helpful. TPU has shown to be reproducible [10], significantly less painful than DE and to lessen anxiety levels during the latent stage of labour [12]. Higher anxiety levels have been shown to be associated with a longer time to delivery [38] and higher degrees of pain [39].…”

“…TPU has several advantages: it is an objective and reproducible method of examination [9,10], easily accessible and less unpleasant than DE during the assessment of labour progress [11,12]. A combination of the Bishop Score and several (perineal) ultrasound parameters have been suggested in previous studies [13,14].…”