Thorp, John M., Jr. (1995). Commentary On: The Effect of Epidural Anesthesia on the Length of Labor. Obstetrical & Gynecological Survey, 50(11)
There exists a strong association between epidural analgesia in labor and dystocia (Martin et al., Obstet Gynecol 1994;83:1045, Survey 1994;49:362). This association has tempted many authors, including the authors of the present study, to imply that epidurals cause dystocia and result in more abdominal deliveries. I would propose an alternative mechanism to explain the observed phenomena. Women with dysfunctional (and thereby longer) labors are more likely than women with normal (and thereby shorter) labors to obtain regional analgesia. Thus, the utilization of epidural analgesia becomes a marker for, not a cause, of dystocia.
Obstetrical & Gynecological Survey
Thorp, John M., Jr.