EP19.13: “Opt‐out” use of intrapartum sonographic assessment at prolonged second stage of labour: a single‐centre experience

To analyse the compliance with intrapartum ultrasound examination after an “opt-out” protocol on prolonged second stage of labour had been introduced in a general obstetric unit since February 1, 2023. Prior to that, 29.7% women had sonographic assessment as directed by the clinician. A retrospective study was conducted among women who delivered by assisted vaginal or second stage Caesarean delivery at Kwong Wah Hospital, Hong Kong, between February 1, 2023 and January 31, 2024. Examination of fetal head position and station with transabdominal and transperineal ultrasound was performed as part of assessment at prolonged second stage, unless reasons were provided. Birth statistics were obtained from Clinical Data Analysis and Reporting System (CDARS). Labour characteristics, demographic data were obtained from labour record. The total maternities and livebirths during the study period were 2,454 and 2,483 respectively. There were 119 assisted vaginal deliveries (3.99% of total livebirths), of which 56 (47.1%) were performed for prolonged second stage of labour. Intrapartum ultrasound assessment was performed in 51 women (91.1%). Ultrasound was not performed in 5 women due to busy labour ward (1), urgent delivery (1), outlet procedure (1) no reason (2). In total, 13/56 procedures (23.2%) required ≥ 3 pulls, including one woman with sequential use of forceps. There was no failed assisted vaginal delivery. The total number of emergency Caesarean deliveries were 483 (19.5%), of which three (0.6%) were performed at second stage of labour for suspected cephalopelvic disproportion. Intrapartum ultrasound assessment was performed in 2 women (66.7%). Changing to an “opt-out” protocol on second stage of labour increased the use of intrapartum sonographic assessment from 29.7% to 91.1%, while the rate of second stage Caesarean section remained low. Combining clinical and sonographic assessment in the second stage seems to be practical in a general obstetric unit.