Utility of intrapartum ultrasound in addition to Bishop score in predicting successful induction of labour

초록

Objectives:The Bishop score has been widely used as a predictivesystem for successful induction of labour. However, the Bishopscore can be subjective, so, it has individual differences. In thisstudy, we investigated performance of Bishop score and intrapartumultrasound before induction of labour to predict successful vaginaldeliveries.Methods:This retrospective study analysed data collected fromsingleton pregnant women who underwent intrapartum ultrasoundbefore induction of labour and gave birth from January 2020 toFebruary 2023 at Korea University Ansan Hospital. Bishop score,angle of progression (AOP), head to perineum distance (HDP), headto symphysis distance (HSD), anterior and posterior cervical angleand cervical length before induction of labour were assessed.Results:Pregnant women who failed induction of labour had alower Bishop score, a narrower AOP, and a longer cervical lengththan women who had a successful vaginal delivery (p=0.001,0.033, 0.022). The receiver operating characteristic curve for Bishopscore, angle of progression and cervical length demonstrated an areaunder the curve (AUC) 0.677, 0.608 and 0.673 respectively. Thecombination of these three demonstrated a more accurate predictionwith an AUC of 0.761 (95%CI 0.65 to 0.87).Conclusions:Sonographic angle of progression and cervical lengthcan assist in predicting successful vaginal delivery and performedbetter with Bishop score.