Phillips J C, Hochberg C J, Petrakis J K, Van Winkle J D
Am J Obstet Gynecol. 1977 Oct 1;129(3):316-23. doi: 10.1016/0002-9378(77)90790-6.
The effects of epidural analgesia on the duration of labor have been a controversal subject since its increased use in recent years. A total of 598 patients receiving this form of analgesia were studied as to progress in labor and eventual outcome. The mean cervical changes during epidural analgesia with a single drug, bupivacaine, 0.125%, with epinephrine, 1:200,000, have been calculated. The labor curves are characterized by constant acceleration in dilatation without deceleration at approximately the same rate for nulliparous and multiparous patients after dilatation of 5 cm. has been reached. Examination of maternal and fetal profiles failed to demonstrate any consistent variables that produce abnormal labor.