P14.11: Sonographic assessment of fetal head position during the first and second stage of labor for the prediction of persistent occiput posterior position and labor dystocia

목적: The aim of this study was to perform a preliminary investigation into the predictive values of the position of the fetal occiput measured during the first and second stages of labor by intrapartum ultrasound for persistent occiput posterior (OP) position and labor dystocia. 방법: This was a prospective cohort study, in which 148 primiparous women with singleton pregnancies were enrolled. The women underwent intrapartum transabdominal sonography and the positions of the fetal head were recorded during the first and second stage of labor. We analyzed the correlation between the position of fetal head and labor course and perinatal outcomes. Statistics were performed using SAS 9.2. 결과: 148 pregnancies were evaluated in the first stage of labor, with 126 of these also evaluated in the second stage. 22 pregnancies were not evaluated during second stage because they underwent Cesarean section during the first stage. 51 of 148 fetuses (34.5%) were found to be in an OP position during the first stage of labor. There were 8 cases of OP position during the second stage, and 6 of these (75.0%) were among the 51 fetuses that were found to be in an OP position during the first stage of labor. 19 of 51 cases with OP position during the first stage of labor (37.3%) and 2 of 8 cases with OP position during the second stage of labor (25.0%) underwent Cesarean section owing to arrest disorder. The rates of Cesarean section in OP position group were significantly higher than those in OA position and OT position group (p=0.0024, 0.0374). Perinatal complications occurred more frequently in OP position group than OA position and OT position groups. But there was no statistically significant correlation. 결론: The results of this study suggest that the position of the head during the first and second stage of labor could be useful indicators for predicting the persistent OP position and labor dystocia. Studies with larger sample sizes are needed to confirm these results.