| Objective:Our objective was to investigate the effectiveness and practicality of ultrasound in monitoring labor progress and to predict the mode of delivery.Methods:From November 2018 to July 2019,150 singleton pregnancies with cephalic presentation in the Affiliated Hospital of Zunyi Medical University were included.In the first stage of labor two-dimensional ultrasound was used to measure fetal head position and station,anteroposterior diameter of cervix,angle of labor progress(AOP),head-perineum distance(HPD),so as to evaluate labor progress and predict the mode of delivery.Ultrasound was performed immediately after the confirmation of cervix by transvaginal digital examination and the examination time was no more than 5 minutes and ensure there were no contractions.The examination was performed immediately after labor.For nulliparous women we did that every two hours in latent phase while every hour in active phase.For parous women we did that every hour until the cervix was fully dilated.Results:1.Pregnant women’s compliance:86.67%of pregnant women thought that ultrasound examination was painless than transvaginal digital examination.The NRS score of the ultrasound examination was 1.65±1.58,while that of the transvaginal digital examination was 4.91±2.43.The difference was statistically significant(t=13.81,P<0.01).2.Consistency and validity analysis of ultrasonic examination:the ICCs of the anteroposterior diameter of cervix and fetal head station by ultrasound were0.971[95%CI(0.963,0.977)]and 0.902[95%CI(0.878,0.922)]respectively.The ICCs of the anteroposterior diameter of cervix and fetal head station by digital examination and ultrasound were 0.951[95%CI(0.939,0.961)]and 0.772[95%CI(0.721,0.816)]respectively.It indicated that the repeatability of ultrasonic examination was good and the consistency with digital examination was high.3.There is a linear correlation between ultrasound parameters and transvaginal digital examination values.Linear regression equations:(1)Cervical dilatation=0.082×AOP-4.576(R~2=0.378 P<0.05);(2)Fetal head station=0.06×AOP-6.986(R~2=0.543 P<0.05);(3)Cervical dilatation=-1.006×HPD+9.877(R~2=0.202 P<0.05);(4)Fetal head station=-0.666×HPD-3.235(R~2=0.285 P<0.05)。4.The evaluation of mid-transfer cesarean section by ultrasound parameters:4.1 In nulliparous women,the AOP rate of vaginal delivery group was significantly bigger than that of mid-transfer cesarean section group in latent phase[4.51(2.06,6.50)vs1.67(0.34,3.42)°/h].The HPD rate of vaginal delivery group was bigger than that of mid-transfer cesarean section group in active phase[0.39(0.22,0.69)vs0(0.06,0.26)cm/h].The difference was statistically significant.4.2 The best critical value of AOP rate in latent phase was 4.23°/h and the area under the curve(AUC)was 0.72[95%CI(0.57,0.84),P<0.01],with a sensitivity of 88.24%,specificity of 58.06%,positive predictive value of 55.56%and negative predictive value of 90.00%.The best critical value of HPD rate in active phase was 0.26cm/h and the area under the curve(AUC)was 0.81[95%CI(0.63,0.92),P<0.01],with a sensitivity of 65.38%,specificity of 87.50%,positive predictive value of 43.80%and negative predictive value of 94.40%.Conclusion:Ultrasound can be used to monitor the progress of the first stage of labor,with better reliability and validity,and higher compliance for pregnant women.AOP and HPD rates can be used as predictors of labor process and the mode of delivery. |
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