Labor and delivery outcomes by delivery method in term deliveries in occiput posterior position: a population-based retrospective cohort studyAJOG Global Reports at a Glance

• Published in: AJOG global reports 2022-11, Vol.2 (4), p.100080
• Main Authors: Hannah H. Foggin, MD, Arianne Y. Albert, PhD, Nicole C. Minielly, BSc, Sarka Lisonkova, MD, PhD, Nicole A. Koenig, BA, Erin N. Jacobs, MSc, Geoffrey W. Cundiff, MD
• Format: Article
• Language: English
• Subjects: forceps rotation; malposition; manual rotation
• ISSN: 2666-5778; 2666-5778

BACKGROUND: Occiput posterior is the most common malposition in labor. Deliveries in occiput posterior position have been shown to have higher rates of adverse short-term maternal and neonatal outcomes compared with deliveries in occiput anterior position. There are no guidelines providing recommendations nor summarizing risks of adverse outcomes by delivery method to inform the decision-making process in occiput posterior delivery management. Population-based studies examining the outcomes associated with various management processes of occiput posterior position at the time of labor or delivery are lacking. OBJECTIVE: This study aimed to describe the current management of term singleton occiput posterior deliveries in British Columbia, Canada and to examine the association between different management strategies and adverse outcomes by describing the rates of: occiput posterior malposition; and spontaneous vaginal delivery, operative vaginal delivery, and cesarean delivery from occiput posterior malposition. We also analyzed the rates of adverse labor and delivery outcomes stratified by fetal position and delivery mode, and the interaction effect of occiput posterior position and delivery mode on the rates of adverse outcomes. STUDY DESIGN: This was a retrospective cohort study of cephalic term singleton deliveries in British Columbia from 2004 to 2020, using the British Columbia Perinatal Data Registry. The obstetrical adverse outcome index (a composite of 10 adverse maternal or neonatal events), adverse outcome index subcomponent rates, and adverse outcome index–derived weighted scores were compared between deliveries stratified by fetal position at delivery (occiput posterior or occiput anterior) and occiput posterior deliveries stratified by delivery method. Multivariable log-binomial logistic regression was used to model the adverse outcome index score. RESULTS: Of 306,237 term births, 19% had occiput posterior position during labor, 37% of which persisted in occiput posterior position at delivery. Among occiput posterior deliveries, 27% were spontaneous vaginal deliveries, 8% vacuum, 5% forceps, 1% mixed vacuum-forceps, and 59% were cesarean delivery; this distribution differed from that of occiput anterior deliveries (P