Conclusion: Pain relief in labor with PCEA with ropivacaine at concentrations of 0.075%; 0.1% and 0.125% in combination with fentanyl 2mcg / ml, there was no difference in uterine contractions, fetal heart rate and neonatal Apgar score and other side effects such as itching, back pain, chills, urinary retention... However, ropivacaine 0.125% group reduced the feeling of pulsation and the ability pulsation, increasing the rate of lower limb movement compared to the other two groups (p<0.05).