Prediction value of transperineal ultrasound at the first stage of labor in predicting the delivery mode and time to delivery in primiparous women with a singleton pregnancy

LI Pinghua; ZHOU Ling; DUAN Shupo

doi:10.3969/j.issn.1002-7386.2025.04.016

Abstract：Objective To explore prediction value of transperineal ultrasound(TPUS)at the first stage of labor in predicting the delivery mode and time to delivery in primiparous women with a singleton pregnancy.Methods A total of 120 primiparous women with a singleton pregnancy from May 2021 to May 2023 were selected.The angle of progression(AOP),head perineum distance(HPD)and midline angle(MLA)were measured by TPUS after cervix enlargement of 2-3cm.Delivery outcomes were recorded.According to whether there was a spontaneous vaginal delivery,primiparous women were divided into the vaginal delivery group(n=107)and cesarean section group(n=13).The effectiveness of AOP,HPD and MLA in predicting vaginal delivery was analyzed.Then the women were grouped by the cut-off values of AOP,HPD and MLA,and the vaginal delivery rate and time to delivery between groups were compared.Results There were significant differences in the AOP,HPD,and MLA between the two groups(P＜0.05).The area under the curve(AUC)of AOP,HPD and MLA to predict a vaginal delivery was 0.903,0.818 and 0.663,respectively,with the optimal cut-off of 119°,4cm and 72°,respectively.The median time to delivery in the AOP＜119° group and AOP≥119° group was 82min and 72min,respectively,showing a significant difference(x2=7.441,P=0.006).The median time to delivery in the HPD＜4cm group and HPD≥4cm group was 74min and 82min,respectively,showing a significant difference(x2=6.670,P=0.010).The median time to delivery in the MLA＜72° group and MLA≥72° group was 79min and 82min,respectively,and with no statistically significant difference(x2=1.040,P=0.308).Conclusion AOP and HPD detection in the first stage of labor have good values in predicting vaginal delivery and time to delivery.