Occipito-Posterior Position of the Vertex: A Survey of 750 Cases *Read 12th January 1927.

with the exception that cases have been excluded in which, in addition to abnormal position, labour was complicated by contracted pelvis, placenta previa, or other major abnormalities. The further reservation should be made that the review comprises only those cases in which diagnosis of posterior position was made or confirmed by vaginal examination during labour. In regard to the frequency of posterior position there is a wide difference of opinion, figures ranging from 11 to 30 per cent, being noted in reports from different hospitals. In the Edinburgh Maternity Hospital the position was posterior in approximately 18 per cent, of vertex presentations. The exact incidence is difficult to estimate and of little significance. What is of importance is that the abnormality is the commonest complication of labour with which the obstetrician has to deal, may tax to the utmost his patience, judgment and skill, and is not infrequently attended with serious consequences both to mother and child.