title: Sonographic assessment of fetal occiput position during labor for the prediction of labor dystocia and perinatal outcomes.
abstract: OBJECTIVE
  To evaluate the effect of the occiput posterior (OP) position on dystocia and perinatal outcomes.
  
  
  METHODS
  This was a prospective cohort study of 162 primiparous women. We performed intrapartum sonography, and fetal occiput positions were recorded. The relationships between the position of the occiput and the course of labor and perinatal outcomes were investigated. Statistical analysis was performed using SAS 9.2.
  
  
  RESULTS
  Fifty-six of 162 fetuses were found to be in the OP position during the first stage of labor. Eight (80.0%) of 10 fetuses in the OP position during the second stage were among the 56 that were in OP position during the first stage. The rate of cesarean sections performed in the OP position group during the first stage was significantly higher than the rate in the non-OP position group (37.5% versus 8.5%, p < 0.0001). The duration of the second stage of labor was longer and neonatal complications occurred more frequently in the OP position group during the second stage than in the non-OP position group (77.9  ±  33.4 min versus 52.2  ± 26.6 min, p = 0.0104; 50.0% versus 17.2%, p = 0.0118).
  
  
  CONCLUSIONS
  The OP position may be a useful predicator for labor dystocia that can lead to poor neonatal outcomes.
authors.affiliation: a Department of Obstetrics and Gynecology and.
authors.forename: Sae Kyung
authors.initials: SK
authors.lastname: Choi
authors.affiliation: b Department of Biostatistics , College of Medicine, The Catholic University of Korea , Seoul , Republic of Korea.
authors.forename: Yong Gyu
authors.initials: YG
authors.lastname: Park
authors.affiliation: a Department of Obstetrics and Gynecology and.
authors.forename: Da Hye
authors.initials: da H
authors.lastname: Lee
authors.affiliation: a Department of Obstetrics and Gynecology and.
authors.forename: Hyun Sun
authors.initials: HS
authors.lastname: Ko
authors.affiliation: a Department of Obstetrics and Gynecology and.
authors.forename: In Yang
authors.initials: IY
authors.lastname: Park
authors.affiliation: a Department of Obstetrics and Gynecology and.
authors.forename: Jong Chul
authors.initials: JC
authors.lastname: Shin
mesh_terms: D000328:Adult; D036861:Delivery, Obstetric; D004420:Dystocia / Q000175:diagnosis*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007746:Labor Presentation; D007747:Labor Stage, First; D007748:Labor Stage, Second; D016015:Logistic Models; D011247:Pregnancy; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D016216:Ultrasonography, Prenatal / Q000379:methods*
keywords: Labor presentation; obstetric labor; ultrasonography