Effect of epidural analgesia on labor times and mode of delivery: a prospective study.

Purpose: To assess changes in labor times and delivery outcome in low-risk women requesting pain relief and undergoing epidural analgesia, according to the epidural analgesia schemes. Materials and Methods: Prospective observational study of 499 low-risk women with epidural analgesia. Speed of dilatation (SD) (centimeters of dilatation / hours), speed of lowering of the fetal head through maternal pelvis (SL) (centimeters in lowering / hours), time of active phase of labor (TA), cesarean section (CS), vacuum application (VA) were dependent variables in multivariable linear and logistic regressions. Results: Dilution of ropivacain, fentanyl amount, and volume of the first dose of epidural analgesia did not seem to affect labor times. Epidural analgesia with schemes used in this study favored both the dilatation and the fetal head lowering through maternal pelvis. Every five minutes from the first dose of epidural to the last top-up, SD decreased by about 13% (p = 0.002), SL decreased by about 14% (p < 0.001), and TA increased by about 40% (p < 0.001). Additionally, every five minutes from the first dose of epidural to the last top-up, the odds of an operative vaginal birth (vacuum) increased by 0.7% (p < 0.001). Increasing of number of top-ups independently caused a reduction in odds of undergoing CS (odds ratio 0.434; C.I. 95% 0.219 - 0.859, p = 0.017), without influencing labor times. Conclusion. Epidural analgesia in patients requesting pain relief favors normal course of labor if it is not discontinued or delayed.