Vaginal delivery from the persistent occiput posterior position. Influence on maternal and neonatal morbidity.

We performed a retrospective study of 564 vaginal occiput posterior (OP) deliveries to investigate the influence of this position on maternal and fetal morbidity. The cases were compared to 1,068 controls matched for race, parity and delivery method. The OP group had a higher incidence of severe perineal laceration and episiotomy than the occiput anterior (OA) group. Within the OP group, operative delivery was associated with a higher incidence of severe perineal laceration, vaginal laceration and episiotomy than was spontaneous delivery. Similarly, the OP group delivered by forceps had a higher incidence of severe perineal lacerations, vaginal lacerations and episiotomy than those delivered by vacuum extraction. Mediolateral episiotomy was associated with a lower incidence of severe perineal lacerations than median episiotomy during delivery from the OP position. The infants delivered from the OP position had a higher incidence of Erb's and facial nerve palsy than did those delivered from the OA position. All these injuries occurred following forceps delivery. Vaginal delivery from the persistent OP position is associated with increased maternal morbidity, and operative vaginal delivery from this position is associated with increased neonatal morbidity.