BACKGROUND: Between 3-4% of pregnancies carried to term, the fetuses are in breech presentation. The external version is a maneuver gynecological used to turn a breech in cephalic presentation. For treatment of pain suggests the use of μ agonist remifentanil for fast action and elimination.

OBJECTIVE: To compare the effectiveness of remifentanil for pain management in external version.

PATIENTS: Pregnant for 36 weeks or more with breech presentation who met the inclusion criteria and sign the consent. Participants will be randomized into two groups before the procedure.

Group intervention: paracetamol and remifentanil Control group: paracetamol and placebo DETERMINATIONS: VAS pain level, percentage of success of the maneuver and adverse events.

Statistical Analysis: Comparison of pain recorded by VAS in both groups and comparison of adverse events

Inclusion Criteria:

• Fetuses between weeks 36 and 41 of gestation confirmed by ultrasound with non-cephalic presentation.
• Informed consent signed by the mother or legal representative in his absence.

Exclusion Criteria:

• Fetal anomalies
• Severe hypertension
• Allergy to drug used in the test
• Amniotic fluid index ≥ 5 cm
• Contraindication for vaginal delivery
• Uterine abnormality and impaired coagulation
• Placenta previa
• Rh sensitization
• Multiple gestation
• Ruptured membranes
• Premature detachment of normally inserted placenta
• The mother greater weight to 85kg