<prompt> Persistent occipitoposterior is common in the following type of pelvis:Android pelvisAnthropoid pelvisGynaecoid pelvisPlatypelloid pelvis  <response>: In more than 50 of cases, the occipito-posterior position is associated with either an anthropoid or android pelvis. Persistent occipitoposterior is an abnormal mechanism of the occipito-posterior position where there is malrotation of the occiput posteriorly towards the sacral hollow occipito-sacral position. Delivery may occur spontaneously as face-to-pubis but arrest may occur in this position and is called occipito-sacral arrest. Ref: Textbook of Obstetrics by D C Dutta, 6th edition, Page 365, 369. 