A comparison of factors associated with occiput posterior positioning and outcomes for women delivering infants in persistent occiput posterior versus occiput anterior position

Although most babies rotate to and are delivered in the occiput anterior (OA) position, approximately 5% of babies are delivered in the occiput posterior (OP) position. This fetal position is associated with many risks to mothers and babies such as long labours, postpartum hemorrhage, perineal trauma, caesarean sections, and psychological distress. Maternal hands and knees positioning is often encouraged during labour to help fetuses rotate from the OP to OA position. The purpose of this retrospective chart review study was to compare mothers delivering infants in the OP and OA positions on exposure to hands and knees positioning and other factors associated with OP position, as well as to compare delivery outcomes between groups. Using a sample of women delivering at a mid-sized community hospital, this nested case-control study compared OP and OA delivery groups. One hundred and fifty women delivering term, singleton infants were selected based on OA or OP vaginal delivery positions and were matched according to maternal age, timing of rupture of membranes, and parity. Analytic approaches included Chi-Square, the Mann-Whitney U, student’s t-test, and Fisher’s exact test. A Bonferroni correction was calculated for these analyses to determine statistical significance, yielding a p value of <.005. Women with OP deliveries were significantly more likely to have an instrumental delivery (Χ²(1) = 15.213, p = .000). Second-stage labour was also significantly longer for women delivering OP positioned infants (Mdn = 00:45), compared with women delivering OA positioned infants (Mdn = 00:30), U(1) = 2002.50, p = .003. No significant differences were found between groups regarding maternal exposure to hands and knees positioning, epidural analgesia, induction of labour, obese body mass index, perineal lacerations, episiotomies, postpartum hemorrhage, high infant birth weight (>4000g) and infant Apgar scores ≤7. Fisher’s exact test revealed no significant differences in ethnicity between groups. Mean birth weights were also compared between groups, revealing non-significant results. Although only length of second stage labour and exposure to instrumental delivery revealed statistically significant results, this study provided insight into the morbidity associated with OP labour for a Canadian sample, implications for nursing practice, and direction for further research.Applied Science, Faculty ofNursing, School ofGraduat